WEARABLE AND REPOSITIONABLE VIBRATING METRONOME

Related Applications

This application claims priority to U.S. patent application serial number 11/138,750 for a "Tactile Metronome," U.S. patent application serial number 11/138,751 for a "Multiple Channel Metronome For Use by Split Ensemble or Antiphonal Recorders," U.S. patent application serial number 11,138,752 for a "Multiple Channel Metronome," U.S. patent application serial number 11/138,753 entitled "Vibrating Transducer with Provision for Easily Differentiated Multiple Tactile Stimulations," and U.S. patent application serial number 11/138,754 for a "Multiple Channel Metronome for Use by Split Ensemble or Antiphonal Recorders," each of which applications were filed on May 26, 2005.

All of the aforementioned applications are incorporated herein by reference. Additionally, the full disclosures of U.S. patent application serial number 11/138,755 entitled "Tactile Rhythm Generator," also filed May 26, 2005, PCT application Serial No. PCT/US03/23633 entitled "Tactile Metronome," filed JuL 29, 2003, and U.S. patent application Ser. No. 10/306,263 entitled "Tactile Metronome," filed Nov. 27, 2002, are incorporated herein by reference.

Technical Field The present invention relates to music technology. More particularly, the invention relates to a metronome that has one or more transducers and a separately housed digital input device, such as a computer or a portable programmable consumer electronics device, which remotely controls the timing and/or rhythm generated by the tranducer(s).

Background Art

The metronome is well established as a fundamental tool of music education. Having been developed before the advent of the electrical apparatus, the traditional metronome comprises a mechanical assembly adapted to generate a clicking sound at a desired beat frequency. With the advent of modern electronics a very precise audio output may now be produced or, as is particularly useful for the music education of deaf persons, the output signal from the metronome may be communicated with a visual indicator such as a flashing light.

While the improvements made possible through technology are meritorious, they generally serve only to better implement a fundamentally flawed method. In particular, the

audio nature of the metronome, which is apparently a holdover from the days of primitive technology, is distracting to the musician and, in at least some musical environments, ineffective due to the inability of the musician to clearly hear the audio signal. Additionally, the audio signal is wholly inappropriate for use by the hearing impaired. While this latter issue has been at least addressed through metronomes with visual outputs, it is noted that the use of the visual indicator mandates that the musician completely memorizes his or her music. Additionally, traditional metronomes are self-contained. As a result, it is cumbersome for a conductor, bandleader or lead musician to control the output of a metronome being used by another. Further, such traditional metronomes can be used only by multiple musicians in close proximity one to another. Still further, the use of multiple traditional metronomes by multiple musicians, especially musicians that are located in different places within a performance venue or musicians that are engaged in an antiphonal performance, is made virtually impossible by the inability to synchronize and/or to stagger the timing of the outputs of the multiple metronomes. Finally, traditional metronomes make no provision for synchronized or time-staggered use by musicians playing different parts of an orchestral musical selection, in which the different musicians may play according to differing rhythmic patterns.

It is therefore an object of the present invention to provide a metronome comprising a central signal generator that is in wireless or wired connection with one or more transducers. Additionally, it is an object of the present invention to provide such a metronome that also may be programmed to provide enhanced capabilities such as, for example, complex output rhythms and/or tactile stimulation designed for the development of articulation. Finally, it is an object of the present invention to provide such a metronome that is also economical to produce and easy to use.

Summary of the Invention

In accordance with the foregoing objects, a metronome is provided that has one or more tactile transducers and a separately and portably housed digital input device or controller that remotely controls the timing and/or rhythm generated by the tranducer(s). The digital input device or controller, which enables a musician to define or select a complex rhythm, including a beat tempo and varying note values (i.e., notes having a duration equal to a fraction of a beat), preferably communicates with the transducer(s) wirelessly. Each transducer is adapted, via a driver circuit that accept digital inputs, to impart multiple differentiable discrete, pulse-like tactile stimulations to the musician wearing it. These

stimulations correspond to different beat divisions of the complex rhythm defined or selected by the musician. Moreover, the transducer-generated signals are preferably tactile, quiet (i.e., less than 30 dB at one meter), and invisible, in order to minimize distraction of others and of the user's own hearing and sight. The inventors have discovered that placing the tactile transducer in contact with the bony areas of the body - such as the musician's spine, shin bone, ankle bone, or wrist bone — yields a more noticeable sensation than placing the transducer in contact with a person's soft tissue, because the bone conducts the vibrations much better than soft tissue. Furthermore, the inventors have discovered that limiting the surface area of the transducer that comes into contact with the body increases the perceived sensation. More particularly, the inventors discovered that giving the transducer with a small, cylindrical housing, provided a more noticeable sensation than a transducer with a flat or rectangular housing.

To reduce the size of the transducer housing, and thereby increase the tactile sensation, the driver circuit and power supply for the transducer is preferably placed in a third portable housing separate from that of the transducer's housing, with wires to carry power and/or control signals connecting the third housing to the transducer's housing.

In its preferred form, the tactile transducer comprises an electric motor having a motor shaft carrying an eccentric weight. The inventors discovered that providing the electric motor with a flexible motor mount within and with respect to the transducer's housing caused the electric motor to wobble, and the shaft of the motor to move in an eccentric orbit. This, in turn, made the tactile sensation even more pronounced. The flexible motor mount may be formed of a cushion, which may be made from foam material or the like. In at least one embodiment of the present invention, the cushion is wrapped substantially about the electric motor, centering the electric motor within the cylindrically shaped tube forming the rigid housing. In order to facilitate manufacture of the vibrating transducer of the present invention, the cushion may be wrapped by a securing sheet such as, for example, a thin paper wrapping, a length of adhesive tape or the like.

These various enhancements enable the tactile transducer to impart differentiable, pulse-like tactile stimulations that are brief enough in duration that the tactile transducer can be used to signal not only the beats of a typical musical rhythm, but also the typically much shorter divisions of each beat. For example, the tactile transducer can be driven to impart a first discrete tactile stimulation corresponding to a first division of a beat and a second discrete tactile stimulation corresponding to a second division of the same beat, wherein the first discrete tactile stimulation is more pronounced than the second discrete tactile

stimulation. The first tactile stimulation has a duration not substantially greater than 100 ms in length, and more preferably about 40 ms in length. The second tactile stimulation has a duration not substantially greater than 50 ms in length, and more preferably about 10 ms in length. Accordingly, the digital input device of the present invention - which may comprise a general purpose laptop computer, a general purpose personal digital assistant, a portable consumer electronics device, or a custom-built portable unit - preferably includes a user interface that enables the musician to independently define both the beat tempo and the beat division of a complex rhythm or beat pattern. One embodiment of the metronome of the present invention includes a belt adapted to be worn by the musician about the musician's waist. A first belt clip is connected to a first housing containing the power supply and driver circuit for the transducer. A second belt clip is connected to the second housing containing the transducer itself. Compressible material is placed intermediate the second housing and the second clip to reduce transference of vibrations between the second housing and the second clip. Furthermore, flexible wires connecting the power supply to the transducer are placed inside the belt to enable the transducer housing to be worn at the small of the musician's back adjacent the musician's backbone while the power supply housing is worn on the musician's side. With the belt clips, the musician can adjust the position of the first and second housings along the belt. Another embodiment of the metronome is designed for use with multiple transducers.

In the multiple-transducer embodiments, the computer or digital controller is preferably equipped to supply different timing and/or rhythm signals to different transducers, and to also control and synchronize the timing and/or rhythms of the various transducers to which it is connected. Provision is made for communication through separate communication channels with multiple, separately located musicians in a manner that provides the musicians individualized beat patterns and/or tempos through their own transducers, which may be co- located with, or located remotely from, a signal generator under the control of a conductor, bandleader, lead musician, music instructor or the like, the individualized communications being synchronized to account for the time of sound travel between the musicians and their audience.

In another, even more advanced embodiment, the computer or controller collectively controls the timing and/or rhythms of the transducers but with time shifts between each metronome. The time shifts may either be user-determinable or automatically determined to

correct for the time it takes for sound to travel from the disparately spaced musicians to a target area.

In yet another multiple-transducer embodiment, each transducer is associated with a receiving unit that has its own secondary user interface to enable the musician to define or select a second beat pattern local to the associated receiving unit and to select between a remote-control channel and a local control channel. Selection of the remote control channel causes the tactile transducer to impart stimulations corresponding to the complex rhythm defined or selected by the digital input device and wirelessly received from the signal generator. Selection of the local control channel causes the tactile transducer to impart stimulations corresponding to the second beat pattern.

For embodiments comprising wireless transmission of the generated signals, the transducer unit (or units) of the present invention generally comprises a receiver, for receiving the signal transmitted from the transmitter of the base unit, and a transducer, for producing according to the received signal a stimulation perceivable by the musician using the transducer unit. Additionally, each transducer unit may comprise a driver circuit as may be necessary to convert the output from the receiver to a signal appropriate for use by the transducer associated with the transducer unit. Likewise, a driver circuit is also provided in association with the base unit for each hardwired channel from the base unit as appropriate for use by the transducer associated with each particular hardwired channel. Although any wireless technology, such as, for example, an infrared transmission system, may be utilized for implementation of the present invention, it is preferable to utilize a radio frequency transmission system as a radio frequency transmission system generally has greater range capability than does an infrared system and is also generally more impervious to varying lighting conditions and the presence of obstructions between the base unit and a remotely located transducer unit. Additionally, an appropriate radio frequency transmission system may generally be as readily and economically implemented as any other wireless technology.

Finally, many other features, objects and advantages of the present invention will be apparent to those of ordinary skill in the relevant arts, especially in light of the foregoing discussions and the following drawings, exemplary detailed description and appended claims.

Brief Description of the Drawings

FIG. IA shows, in a functional block diagram, one embodiment of a multiple channel metronome.

FIG. IB shows, in a functional block diagram, an embodiment of a measurement device, for use with the multiple channel metronome of FIG. IA, for determining the time of sound travel between distant locations.

FIG. 2 shows, in a schematic diagram, details of one embodiment of a transmitter circuit, as depicted in FIG. IA, appropriate for implementation of the base unit of the metronome of the present invention.

FIG. 3 shows, in a schematic diagram, details of one implementation of a receiver circuit, as depicted in FIG. IA, appropriate for implementation of the remote transducer unit of the metronome of the present invention, FIG. 4 shows, in a schematic diagram, details of one embodiment of a power conditioning circuit as may be implemented for use with the transmitter circuit of FIG. 2 and/or the receiver circuit of FIG. 3.

FIG. 5 shows, in a schematic diagram, details of one embodiment of a driver circuit, as depicted in FIG. IA, appropriate for operation of the vibrating transducer of FIG. 6. FIG. 6 shows, in an exploded perspective view, the preferred embodiment of a vibrating transducer as has been found to be optimum for use with the transducer unit of FIG. IA.

FIG. 7 shows, in a cross sectional side view, details of the arrangement of the internal components of the vibrating transducer of FIG. 6. FIG. 8 shows, in a cross sectional end view taken through cut line 8-8 of FIG. 9, additional details of the arrangement of the internal components of the vibrating transducer of FIG. 6.

FIG. 9 shows, in a partially cut away perspective view, a representation of the forces produced in the operation of the vibrating transducer of FIG. 7. FIG. 1OA through 1OF show, in schematic representations generally corresponding to the view of FIG. 8, changes in the relative positions of various internal components of the vibrating transducer of FIG. 6, which changes occur as a result of the operational forces represented in FIG. 9.

FIG. 11 shows, in a multiple part musical score, a typical orchestral arrangement with which the multiple channel metronome of FIG. IA may be utilized.

FIG. 12 shows, in a series of voltage waveforms corresponding to the musical score of FIG. 11, representative signals as may be generated by the signal generator of FIG. IA for operation through the driver circuit of FIG. 4 of the vibrating transducer of FIG. 5, the waveforms having characteristics such that the tempo, rhythms and timing of measures,

including delays to account for distinct location of musicians, of the score of FIG. 11 may be readily perceived by the individual musicians employing the metronome of the present invention to perform their respective parts.

FIG. 13 shows, in a functional block diagram, another embodiment of a system for driving a vibrating transducer.

FIG. 14 shows, in schematic diagram, embodiments of electronic circuits that may be utilized in the system of FIG. 13 for differentiating between two digital signals for driving the vibrating transducer of FIG. 6.

FIG. 15 shows a schematic diagram of another embodiment of a power conditioning circuit.

FIGS. 16A and 16B show, in voltage time plots, typical signals generated by an electronic metronome for divisional and downbeats, respectively, or by telegraph devices for dashes and dots, respectively, or the like.

FIG. 17A shows, in a voltage time plot, the signals of Figures 16A and 16B after being passed in a pattern through an envelope detector, as implemented in the design of FIG. 14.

FIG. 17B shows, in a voltage time plot, the same composite signal after further being passed through a class C amplifier, as also implemented in the design of FIG. 14.

FIG. 18 shows, in a voltage time plot, the signal of FIG. 17B after being low pass filtered by a first order R-C filter, as implemented in the design of FIG. 7A.

FIGS. 19 A and 19B show, in voltage time plots, output signals from first and second monostable multivibrator, or "one-shot," circuits, as implemented in the design of FIG. 14, the output from the first being the result of inputting the signal of FIG. 16A to the circuit of FIG. 14 and the output from the second being the result of inputting the signal of FIG. 16B to the circuit of FIG. 14, whereby the first is used to drive the vibrating transducer of Figure 1 to produce a tactile stimulation easily recognized as a divisional beat, dash or the like and the second is utilized to drive the vibrating transducer of FIG. 1 to produce a tactile stimulation easily recognized as a downbeat, dot or the like.

FIG. 20 depicts an embodiment of a digital input device (which may incorporate a signal generator) for use either in conjunction with either the base unit or the transducer unit of FIG. 1.

FIG. 21 depicts an embodiment of a metronome comprising a transducer and a transducer controller or driver circuit that are in separate housings, connected by power wires, and attached to separate clips that can be affixed to a belt.

FIG. 22 shows, in perspective view, one embodiment of a tactile metronome as operably employed by a musician.

Disclosure of the Invention Although those of ordinary skill in the art will readily recognize many alternative embodiments, especially in light of the illustrations provided herein, this detailed description is exemplary of the preferred embodiment of the present invention, the scope of which is limited only by the claims appended hereto.

Referring now to FIG. IA, in particular, the multiple channel metronome 15 of the present invention is shown to generally comprise a base unit 20, for generating and, in at least one embodiment of the present invention, transmitting timing signals, and a plurality of transducers 35, for producing, according to the signals generated by the base unit 20, stimulations perceivable by a plurality of musicians, who may be co-located with the base unit or located at one or more places remote from the base unit 20, but in any case are located, individually or in groups, apart from one another. In embodiments contemplating location of one or more musicians at locations remote from the base unit 20, the metronome further comprises one or more transducer units 29 for receiving signals transmitted from the base unit, as will be better understood further herein. An unlimited number of transducer units 29 may be implemented so long as each receiver 31 of the transducer units 29 is tuned to receive the signals output from one of the transmitters 26 of the base unit 20.

As shown in FIG. IA, the base unit 20 of the metronome of the present invention comprises a signal generator 23 in electrical communication with a digital input device or controller 21 and, preferably, one or more transmitters 26. The digital input device 21 may be a general purpose computer, a general purpose personal digital assistant, some other type of personal portable consumer electronics device, or even a MIDI instrument. In any case, it is preferably programmed to facilitate user selection of the characteristics of the signal generated by the signal generator 23 and, in embodiments comprising at least one transmitter 26, for controlling the transmission through the transmitter 26 of generated signals. The digital input device 21 can transmit a complex beat pattern to the signal generator 23, which generates corresponding signals in response thereto. The signal generator 23 may also have memory storage for storing the complex beat patterns received from the digital input device 21, so that the signal generator 23 can output signals, as directed by the user, at a time when the signal generator 23 is not in electrical communication with the digital input device 21.

The digital input device 21 preferably includes a user input system, such as a touch screen control and/or a computer interface such as a USB port, wireless interface or the like, buttons or dials, for use in inputting user selections. The digital input device 21 also preferably includes a display 22, which may comprise a graphical user display such as a liquid crystal display, a simpler display such as a light emitting diode display, or any other substantially equivalent structure, for use in monitoring user selections.

The digital input device 21 may be programmed to control the signal generator 23 for the generation of individualized signals for output to each channel from the base unit 20. Additionally, the digital input device 21 may be programmed to control synchronization of the generated signals such that some of the generated signals may be delayed with respect to others, as will be better understood further herein. In the preferred embodiment of the present invention, the digital input device 21 is thus adapted to produce multiple outputs having differing complex rhythmic patterns, but that are synchronized in time such that, for example, one musician may receive stimuli indicating quarter notes, another may receive stimuli indicating eighth notes, another may receive stimuli indicating a rhythmic pattern and so forth, yet all receive stimuli timed to indicate common measure beginnings from the perspective of the audience for the musicians' performance. In particular, by way of example, one group of musicians located at a first location may receive stimuli at a first time while a second group of musicians located at a second location, farther from the audience than the first location, may receive stimuli at a second time slightly ahead of the first time. The result from the perspective of the audience will be that the audience will hear each group in unison as if all were performing in close proximity to one another.

The metronome 15 of the present invention may also be provided with a sound timer 70, an exemplary embodiment of which is depicted in FIG. IB, for determining the speed of travel of sound between musicians or between musicians and their audience. As shown in the figure, the sound timer 70 may comprise a sound wave source 71 adapted for communication with a delay calculator 78. The sound wave source 71 comprises a tone generator 72 and a preferably radio frequency transmitter 74 in communication with a controller 76. The delay calculator 78 comprises a preferably radio frequency receiver 79 and a microphone 81 in communication with a controller 82 having associated therewith a display 83.

In use of the sound timer 70, a user causes the sound wave source 71 to simultaneously generate a radio frequency output and an audible output by actuating a trigger 77 provided in association with the controller 76 of the sound wave source 71. The radio frequency output is transmitted from the sound wave source through an antenna 75, provided

in electrical communication with the radio frequency transmitter 74, and the audible output is transmitted from the sound wave source 71 through a speaker 73, provided in electrical communication with the tone generator 72. The delay calculator 78 is adapted to receive and recognize both the radio frequency output and the audible output from the sound wave source 71. In particular, the delay calculator 78 receives the radio frequency output through an antenna 80 in electrical communication with the radio frequency receiver 79. Likewise, the audible output is received through the microphone 81.

The radio frequency transmission from the sound wave source 71, traveling at the speed of light, will be received virtually instantaneously by the delay calculator 78 while the audible output from the sound wave source 71 will travel at the much lesser speed of sound. The controller 82 of the delay calculator 78 is programmed to start a clock upon reception at the delay calculator 78 of the radio frequency output from the sound wave source 71 and to stop the clock upon reception at the delay calculator 78 of the audible output from the sound wave source 71. The time elapsed on the clock is the time of travel of sound between the location of the sound wave source 71 and the delay calculator 78, which may be output through the display 83 of the delay calculator 78 for use, as will be described in more detail further herein, by the metronome 15 of the present invention.

In order to facilitate recognition of the trigger radio frequency output and the audible output at the delay calculator 78, the radio frequency transmitter 74 is preferably adapted to output a carrier signal modulated by a code pattern. Likewise the tone generator 72 is adapted to output a particular audio frequency or simple pattern of audio frequencies. Additionally, the sound timer 70 may be adapted to send and receive several transmissions, in which case the controller 82 of the delay calculator 78 is preferably programmed to check for consistency between the several timing calculations before rendering a valid output through its display 83.

Although the sound timer 70 of the present invention has been described as preferably utilizing a radio frequency transmission system for triggering of the clock of the delay calculator 78, any other instantaneous signaling system may be utilized. For example, an infrared or other optical transmission system may be implemented or a hardwired electrical connection may be maintained between the sound wave source 71 and the delay calculator 78.

For embodiments of the metronome 15 of the present invention comprising wireless transmission of the generated signals, the transducer unit 29 (or units) of the present invention generally comprises a receiver 31, for receiving the signal transmitted from the

transmitter 26 of the base unit 20, and a transducer 35, for producing according to the received signal a stimulation perceivable by the musician using the transducer unit 29. Additionally, each transducer unit 29 may comprise a driver circuit 53 as may be necessary to convert the output from the receiver 31 to a signal appropriate for use by the transducer 35 associated with the transducer unit 26. Likewise, a driver circuit 53 is also provided in association with the base unit 20 for each hardwired channel from the base unit as appropriate for use by the transducer 35 associated with each particular hardwired channel.

Any wireless technology, such as, for example, an infrared transmission system, may be utilized for implementation of the present invention. Applicant has found it preferable to utilize a radio frequency transmission system. A radio frequency transmission system generally has greater range capability than does an infrared system and is also generally more impervious to varying lighting conditions and the presence of obstructions between the base unit 20 and a remotely located transducer unit 29. Additionally, an appropriate radio frequency transmission system may generally be as readily and economically implemented as any other wireless technology. Although radio frequency transmission is preferred, a lower power, short-range radio frequency transmission system, having a range of less than one kilometer will be more than adequate, given that it is expected that the transducers of the present invention will be located within the same general vicinity.

Referring now to FIGS. 2 through 4, in particular, an exemplary radio frequency transmission system, as may be utilized in implementation of the present invention, is shown to generally comprise a radio frequency transmitter 26 (depicted in FIG. 2) and a radio frequency receiver 31 (depicted in FIG. 3). Each receiver 31 is tuned to receive the signal output from one of the transmitters 26. Additionally, as shown in FIG. 4, the radio frequency transmission system may also comprise power conditioning and regulation circuitry 57 as may be necessary for operation of both the transmitters 26 and the receivers 31.

Referring now to FIG. 2, it is shown that an appropriate transmitter 26 may be implemented utilizing a commercially available, off-the-shelf digital transmitter module 27. One such module 27 is the model TX-DFM-5V digital frequency modulated ("FM") transmitter module available from AUREL S. p. A. of Modigliana, Italy, having an operating range of about 100 meters. In implementing the base unit 20 with such a transmitter 26, the signal output from the signal generator 23 is fed, preferably through a shielded cable 24 to prevent interference, into the manufacturer-designated input pin of the integrated transmitter module 27. The integrated transmitted module then modulates the input signal onto a carrier radio frequency. The modulated carrier radio frequency is then fed from the manufacturer-

designated output pin of the integrated transmitter module 27 to an antenna 28 for transmission to the remotely located transducer unit 29. Additionally, as shown in FIG. 2, a buffer 25 may be provided in the channel between the signal generator 23 and the transmitter 26 to ensure that the signal output from the signal generator 23 is electrically compatible with the integrated transmitter module 27. (It is noted that for clarity the exemplary digital transmitter module 27 described is a single frequency system; in implementations comprising multiple radio frequency transmission channels a slightly more complex module having multiple frequency selections will be implemented.)

Referring now to FIG. 3, it is shown that an appropriate receiver 31 may be implemented utilizing a commercially available, off-the-shelf digital receiver module 32 compatible with the transmitter module 27. One such module 32 is the model RX-DFM-5V digital FM receiver module also available from AUREL S. p. A. of Modigliana, Italy. In implementing the transducer unit 29 with such a module 32, the signal transmitted from the base unit 20 is received through an antenna 30 into the manufacturer-designated input pin of the integrated receiver module 32. The integrated receiver module 32 demodulates the signal placed on the carrier signal from the carrier signal and outputs the resulting signal, which is essentially the signal output from the signal generator 23 of the base unit 20, through the manufacturer-designated output pin from the integrated receiver module 32. The output signal is then fed to the transducer 35 either directly or, if necessary, through a driver circuit 53, as will be discussed in more detail further herein. In any case, Applicant has also found it desirable to provide a squelch function 33 in association with the integrated receiver module 32 to prevent unintended operation of the transducer 35 such as may occur if the receiver 31 should pick up radio frequency interference or noise through its antenna 30. Typical integrated receiver modules 32 are available off-the-shelf with this feature, implementation requiring only the provision of a multi-turn potentiometer 34 at the manufacturer-designated pins of the integrated receiver module 32. (Again, as with the transmitter module 27, it is noted that for clarity the exemplary digital receiver module 32 described is a single frequency system; as before, in implementations comprising multiple radio frequency transmission channels a slightly more complex module having multiple frequency selections will be implemented.)

As shown in FIG. 4, and previously discussed, both the transmitter 26 and the receiver 31 may be provided with power conditioning and regulation circuitry 57. As shown in the figure, such circuitry 57 may include an integrated voltage regulator 58 for maintaining a constant voltage for powering of the transmitter 26 and/or receiver 31. Additionally, one or

more capacitors to ground may be provided to filter out high frequency noise as may be expected in the implementation of any radio frequency transmission system. Still further, however, such a circuit 57 preferably comprises an ON-OFF switch 59 and may also include a power on indicator 60, which may be readily implemented with a light emitting diode ("LED") connected to the unregulated power bus through a current limiting resistor.

As previously discussed, the base unit 20 (for hardwired channels) and the transducer units 29 (for wireless channels) of the metronome 15 of the present invention may each comprise a driver circuit 53 for interfacing with the transducers 35. Importantly, it is noted that implementations utilizing transducers 35 comprising an electric motor will typically require a driver circuit, such as the driver circuit 53 shown in FIG. 5, comprising an output amplifier 54, which enables logical level signals, such as output from the digital input device 21 or the above-described receivers 31, to drive an electric motor (such as is utilized in the preferred implementation of a vibrating transducer 36 described in detail further herein). This requirement stems from the fact that such an electric motor will generally have a current requirement beyond the capabilities of most low power solid state components. Additionally, in such implementations, the driver circuits 53 will also require implementation of a power conditioning circuit 56 having the capability to prevent and/or suppress voltage spiking, such as may be expected in response to the highly inductive load typical of the type of electric motor utilized in the implementation of the vibrating transducer 36. As shown in FIG. 5, an exemplary output amplifier 54, as is appropriate for use with the vibrating transducer 36 described further herein, comprises a 2N3904NPN BJT transistor Ql, configured as an emitter follower, coupled with a TIP42 high current PNP transistor Q2 in a TO-220 heat dissipating package, for providing the necessary current for operation of the electric motor 40 of the vibrating transducer 36. The output amplifier 54 as shown may be considered a two stage, high current emitter follower. The power conditioning circuit 56, which is preferably provided to prevent and/or suppress voltage spiking, such as may be expected in response to the highly inductive load typical of the type of electric motor 40 utilized in the implementation of the vibrating transducer 36 may be implemented by tying a 10 μF electrolytic capacitor Cl to ground from the 9- V power bus from, for example, a 9- V battery BAT. The electrolytic capacitor Cl will temporarily supply additional current to the 9- V bus as may be required to compensate for transients resulting from the draw upon the output amplifier 54 caused during startup of the electric motor 40 of the vibrating transducer 36. Additionally, the power conditioning circuit 56 preferably comprises an ON-OFF switch SWl and may also include a power on indicator, if desired.

In order to adjust the "feel" of the metronome, as implemented with a tactile vibrating transducer 36, the output from the output amplifier 54 is preferably fed through an output power level selector 55 to an output jack J2, into which the power cord plug 43 of the power cord 42 to the electric motor 40 of the vibrating transducer 36 may be operably inserted. As shown in FIG. 5, the output power level selector 55 preferably comprises a 22 ω resistor R2, which is selectively placed in series with the output circuit by selecting the appropriate position of a single pole, single throw switch SW2. Although Applicant has found that 22 ω is an appropriate value for the resistor R2, it is noted that the value is selected empirically in order to obtain the user desired tactile feel for the "low" output selection. Additionally, the resistor R2 may be replaced with a potentiometer, thereby providing a fully adjustable output power level.

Although the driver circuit 53 has been described as being integral with either the base unit 20 or, if appropriate, the transducer units 29, it should be appreciated that the present invention contemplates that any necessary driver circuit may be provided as part of the transducers 35. In this manner, the base unit 20 or transducer units 29 may be utilized with virtually any type of transducer 35, the driver circuits being adapted to provide all necessary electrical compatibility between the chosen transducer 35 and the output of the digital input device 21 or the receivers 31. In such implementations, the driver circuits should be provided with an input jack Jl for receiving signals from the base unit 20 or receivers 31. Referring now to the FIGS. 6 through 10 in particular, a preferred embodiment of a tactile, substantially inaudible transducer, as preferred for use in implementing the metronome of the present invention, is shown to comprise a vibrating transducer 36 having the unique ability to produce multiple easily differentiated tactile stimulations. As shown in the figures, such a vibrating transducer 36 generally comprises an electric motor 40 having attached thereto an eccentric weight 45 and encased within a rigid housing 37. As is typical with pager transducers and the like, operation of the electric motor 40 turns a shaft 46 upon which the eccentric weight 45 is mounted with, for example, a pin 47. Rotation upon the shaft 46 of the eccentric weight 45 produces a vibratory effect upon the motor 40 resulting from the forward portion 44 of the motor 40 attempting to shift laterally outward from the nominal axis of rotation 48 of the shaft 46, as depicted by the centrifugal force lines F in FIG. 9.

In typical implementations of this principle, the electric motor is rigidly fixed to some body such as, for example, a pager or cellular telephone housing with mounting clamps, brackets or the like. In the present implementation, however, unlike the vibrating transducers

of the prior art, the electric motor 40 is encased within a rigid housing 37 by the provision of a flexible motor mount 49, which allows the forward portion 44 of the electric motor 40 to generally wobble within the rigid housing 37 as the eccentric weight 45 is rotated upon the motor shaft 46. In this manner, the resultant forces F are the product of much greater momentum in the eccentric weight 45 than that obtained in the fixed configuration of the prior art.

In the preferred implementation, as particularly detailed in FIGS. 6 through 9, the flexible motor mount 49 generally comprises a wrapping of preferably foam cushion material 50, which is sized and shaped to snuggly fill the space provided between the electric motor 40 and the interior of the rigid housing 37. The inventors have found that a urethane, open cell foam tape made by 3M ^® and identified by part number 4016 comprises a suitable source of foam cushion material 35. The foam tape has a nominal thickness of 1/16* of an inch (1.6 mm) with a tolerance of between 0.045 and 0.08 inches (1.14 to 2.03 mm) and an approximate density of 11 pounds/ft ³ or 175 kg/m ³ (which is considerably less than the approximately 1100-1200 kg/m ³ of rubber). The foam tape has a tensile strength of about 140 psi or 965 kPa. The foam also has a compression deflection property (i.e., the force it takes to compress a standardized test specimen 25% of its height) of between about 10 and 82.8 kPa, and a compression set % loss (i.e, the amount, measured in percentage, by which the test specimen fails to return to its original thickness after being subjected to a standard compressive load or deflection for a fixed period of time) of between about 5 and 12%.

To facilitate manufacture of the vibrating transducer 36, as generally depicted in FIG. 6, the foam cushion 50 may be held in place about the body of the electric motor 40 with a cushion securing sheet 52, which may comprise a thin paper glued in place about the cushion 50, thin adhesive tape or any substantially equivalent means. To complete the manufacture of the vibrating transducer 36, the cushioned electric motor 40, with 5 eccentric weight 45 attached to its shaft 46, is inserted into the rigid housing 37 and secured in place by the application of epoxy 39 into the open, rear portion 38 of the housing 37. Once inserted, the foam cushion material 35 has a substantially uncompressed "interference fit" within the rigid housing 21. The epoxy 39 also serves to stabilize the power cord 42 to the rear portion 41 of the electric motor 40, thereby preventing accidental disengagement of the power cord 42 from the electric motor 40.

Referring now to FIGS. 8 through 10 in particular, the enhanced operation of the vibrating transducer 36 is detailed. At the outset, however, it is noted that in order to obtain maximum vibratory effect, the rigid housing 37 is provided in a generally cylindrical shape,

as will be better understood further herein. In any case, as shown in the cross sectional view of FIG. 8, and corresponding views of FIGS. 1OA through 10F ₃ the forward portion 44 of the electric motor 40 is encompassed by the forward portion 51 of the foam cushion 50. At rest, i.e. without the electric motor 40 in operation, the electric motor 40 is substantially uniformly surrounded by the foam cushion 50, as shown in FIG. 1OA.

Upon actuation of the electric motor 40, however, the centrifugal forces F generated by the outward throw of the eccentric weight 45 causes the axis of rotation 48 of the motor's shaft 46 to follow a conical pattern, as depicted in FIG. 9. As a result, the forward portion 44 of the electric motor 40 is thrown into the forward portion 51 of the foam cushion 50, depressing the area of cushion 50 adjacent to the eccentric weight 45 and allowing expansion of the portion of the cushion 50 generally opposite, as depicted in FIGS. 1OB through 1OF corresponding to various rotational positions of the eccentric weight 45.

As is evident through reference to FIGS. 1OB through 1OF, the cooperative arrangement of the cushion 50 about the electric motor 40, as also enhanced by the cylindrical shape of the rigid housing 37, allows the eccentric weight 45 to build greater momentum than possible in embodiments where the motor is rigidly affixed to a body. As the forward portion 51 of the foam cushion 50 compresses under the centrifugal forces F of the eccentric weight 45, however, a point is reached where the foam cushion 50 is no longer compressible against the interior wall of the rigid housing 37 and the forward portion 44 of the electric motor 40 is repelled away from the interior wall toward the opposite portion of interior wall.

The result is a vibratory effect much more pronounced than that obtained in prior art configurations calling for the rigid affixation of an electric motor to a housing. Additionally, Applicant has found that the resulting pronounced vibratory effect is generally more perceptible to the human sense of touch than is that produced by prior art configurations. In particular, small differences on the order of tens of milliseconds or less in duration of operation of the vibrating transducer 36, i.e. duration of powering of the electric motor 40, are easily perceived and differentiated. As a result, this implementation of the vibrating transducer 36 is particularly adapted for implementation of the metronome 15 of the present invention, which preferably comprises provision for distinct tactile stimuli representing dominant beats versus divisional beats as well as the generation and communication of complex rhythms, which may require very quickly perceived stimulations with very little pause therebetween. An embodiment of a transducer driving circuit capable of producing easily differentiable signals is described further below in connection with FIGS. 13-19B.

Turning now to FIGS. 11-12, the metronome 15 of the present invention is preferably adapted to impart to a musician, or plurality of musicians, tactile stimulations indicative of tempo and measure timing, as shown in the lower score of FIG. 11, as well as of tempo, measure timing and complex rhythmic patterns, as shown in the upper scores of FIG. 11. In particular, the preferred embodiment of the present invention contemplates imparting tempo information by the timing of the beginning of signal outputs from the signal generator 23 of the base unit 20. In order to differentiate dominant beats, indicative of the beginning of a measure, from other beats in the measure, or to differentiate between the beginning of a beat subdivided into a triplet from the other beat subdivisions, the signal generator 23 is adapted under the control of the digital input device 21 of the base unit 20 to produce signal outputs of at least two different durations. The longer duration beat (e.g., between about 30 and 100 ms in length, more preferably 40 ms long) will be noticeably perceived by the musician or plurality of musicians as being of much greater intensity than the shorter duration beat (e.g., between about 5 and 25 ms in length, more preferably 10 ms long), especially when imparted through the foregoing described vibrating transducer 36. As shown in the lower timing plot of FIG. 12, the digital input device 21 is programmed to implement these aspects of the present invention by simply effecting at a set tempo a repeating pattern of output pulses from the signal generator 23 representing the downbeats and divisional beats.

Again, as shown in the upper scores of FIG. 11 and corresponding upper timing plots of FIG. 12, the metronome of the present invention is preferably adapted to impart to a musician, or plurality of musicians, tactile stimulations indicative of not only tempo and measure timing, but also complex rhythmic patterns. In this case, the digital input device 21 of the base unit 20 is preferably programmed to "follow" the score of a musical selection chosen by the conductor, bandleader, music instructor, lead musician or the like. In the alternative, however, the digital input device 21 may be pre-programmed with a plurality of rhythmic patterns, which may be simply selected through user input to the digital input device 21. The latter will have great utility in mastering basic rhythms. In any case, the preferred embodiment of the present invention contemplates that an appropriate programming interface be provided to allow the conductor, bandleader, music instructor, lead musician or the like to input to the digital input device 21 any desired rhythmic pattern or, for that matter, an entire musical score. As shown in the upper time plots of FIG. 12, the digital input device 21 controls the signal generator 23 of the base unit 20 to produce output pulses only when the score calls for a note to be performed, giving greater duration, or intensity, to those pulses corresponding to downbeats.

As shown in the timing plots of FIG. 12, the measure timings for the various parts (or groups of musicians performing the same part, but in different locations) are shifted in time with respect to one another according to the measurements obtained with the sound timer 70 and input to the base unit 20. For example, as shown in the timing plot, the second set of pulses is delayed with respect to the first set by time At ₁ and the third set of pulses is delayed with respect to the first set by time δt ₂ . In this example, musicians performing the first score at a location far from the audience, musicians performing the third score close to the audience and musicians performing the second score a distance in between may all be heard in unison by the audience. Likewise, the metronome 15 of the present invention may be utilized to produce perceptible delays between performances, thereby creating an echo effect for antiphonal performances.

Returning back to FIG. IB, the sound timer 70 (FIG. IB) or a substantially equivalent system may be utilized, prior to the time of performance, to measure the acoustics of the performance venue. In particular, the time of sound travel between the locations for the various musicians and their audience is measured. Once the times are obtained, the times are input to the base unit 20 of the multiple channel metronome 15 through the provided user input interface.

At the time of performance (or rehearsal, etc.), each musician affixes his or her transducer 35 in a minimally obtrusive location utilizing a strap or the like. The musician then connects the electrical cable 42 between the transducer 35 and the base unit 20 or a receiver 31 by inserting the standard plug 43 into the output jack from one channel of the base unit 20 or from a transducer unit 29 tuned to a wireless channel from the base unit 20. The output power level selector 55, which is preferably provided as previously described, is then utilized to adjust the "feel" of the metronome of the present invention. With the transducers 35 positioned as desired for each musician making use of the metronome 15 of the present invention, a conductor, bandleader, music instructor, lead musician or the like utilizes the provided digital input device 21 and display 22 to set, on a per channel basis, the beats per minute, the number of beats per measure, and, if desired, the number of divisions per beat to be generated by the signal generator 23. In any case, with the transducers 35 in proper position and the base unit 20 set up as desired, the transmitters 26 and receiver 31 or receivers, if utilized, are powered on and the musicians may perform their musical instruments of choice with the metronome under the centralized control of the conductor, bandleader, music instructor, lead musician or the like.

FIG. 13 depicts another embodiment of a tactile stimulation system 138 for driving a vibrating transducer 36. The tactile stimulation system 138 comprises a digital signal receiver or generator 139 and a signal conditioning circuit 140. The digital signal receiver or generator 39 may take any of a variety of forms, but in any case is adapted to generate a driving signal for the vibrating transducer 36 in whatever tempo, duration, complex rhythm or the like is appropriate for the application for which the vibrating transducer 36 is to be utilized. Additionally, a signal conditioning circuit 140 may be implemented whereby a single implementation of the vibrating transducer 36 may be made compatible with a plurality of digital signal receivers or generators 139 having widely diverse electrical output characteristics.

As shown in Figure 14, such a signal conditioning circuit 140 particularly includes an output amplifier 148 with the capability to provide the necessary current for operation of the motor 40 of the vibrating transducer 36 and preferably comprises a power conditioning circuit 151, as shown in Figure 15, having the capability to prevent and/or suppress voltage spiking, such as may be expected in response to the highly inductive load typical of the type of electric motor utilized in the implementation of the vibrating transducer 36. Additionally, the signal conditioning circuit 140 preferably comprises one or more provisions for accepting input signals of varying electrical characteristics. For example, the conditioning circuit 140 of Figure 14 includes an envelope detector 142, which is capable of accepting a burst of voltage pulses as if the burst were a single pulse hawing the same time duration as the burst or, without different result, accepting a single pulse of the same time duration as the burst; at the output of the envelope detector 142, the signals from each will be largely indistinguishable.

Although lesser, or in some cases no, signal conditioning circuit may be required depending upon the electrical characteristics of the signals output from the signal generator 139, an exemplary only signal conditioning circuit 140 is shown in Figure 14 to generally comprise an input jack 141 for receiving signals from the digital signal receiver or generator 139; an envelope detector 142 for transforming various types of input signals into a common characteristic pulse train wherein the time duration of each pulse dictates the output of the vibrating transducer 36; an input amplifier 143 for squaring the output of the envelope detector for further processing; a first signal generator 145 for generating "moderate intensity" or short duration outputs from the vibrating transducer 36 and a second signal generator 146 for generating "intense" or long duration outputs from the vibrating transducer 36; an output amplifier 148 for providing necessary current for operation of the electric motor 124 of the vibrating transducer 36; an output jack 150 for connection, through a power cord

jack 127, of the power cord 126 leading to the motor 40 of the vibrating transducer 36; and other circuitry in support of the foregoing operations and/or for providing additional features, as will be better understood further herein.

Looking closer at the signal conditioning circuit 140 depicted in Figure 14, the envelope detector 142 is shown to comprise a IN4148 diode D2, having its anode connected to terminal Jl-I of input jack 141, and a 0.022 μF capacitor C2 tying the cathode of diode D2 to ground. Signals input at terminal Jl-I of input jack 141 feed into the anode of diode D2 and the envelope of those signals are output at the cathode of diode D2. In order to produce cleaner, more square representations of the resulting signal envelope, facilitating further processing of the input signals, the envelope signal from the envelope detector 142 is passed through an input amplifier 143, which comprises a 2N3904 NPN BJT transistor Ql configured as a common emitter amplifier in Class C operation. A 47 kf2 resistor R2 is selected to limit the current through the base-emitter junction of transistor Ql and to raise the input impedance of the amplifier 143 to a level that will not load down the input envelope signal. A 2.2 kf2 resistor R3 is selected to operate the amplifier 143 in saturation, resulting in a squared off, amplified output at the collector of transistor Ql .

In the next stage of the signal conditioning circuit 140, a pair of signal generators 145, 146 is provided for producing drive signals for operation of the electric motor 124 of the vibrating transducer 36. Each signal generator 145, 146 comprises an LM555N CMOS timer Ul, U2, respectively, configured as a monostable multivibrator or "one-shot." As shown in the figure, the output timing circuit of the first CMOS timer Ul comprises a 68 kf2 resistor R5 and a 0.22 μF capacitor C4 in order to produce a short duration output signal at pin 3 of the CMOS timer Ul of about 10 milliseconds. Upon delivery of the output signal to the electric motor 124 of the vibrating transducer 36, a moderate intensity (or short) tactile sensation will be produced. The output timing circuit of the second CMOS timer U2, on the other hand, comprises a 100 kω resistor R6 and a 0.47 μF capacitor C6 such that the output signal generated at pin 3 of the second CMOS timer U2 is approximately 40 milliseconds in duration, which when delivered to the electric motor 40 the vibrating transducer 36 will produce a distinctly more intense (or long) tactile sensation. In order to differentiate between input signals, the amplified, envelope signal from the collector of transistor Ql, i.e., the output from the input amplifier 143, is delivered "as is" to the trigger pin 2 of the first CMOS timer Ul, but is filtered through a first order R-C low pass filter 144 prior to delivery to the trigger pin 2 of the second CMOS timer U2. This prevents shorter duration input pulses or pulse streams from triggering the second monostable

multivibrator signal generator 145. The R-C filter 144 is readily implemented with a 5.6 kω series resistor and 2.2 μF capacitor to ground.

The output (from pin 3 of CMOS timer Ul) of the first monostable multivibrator signal generator 145 and the output (from pin 3 of CMOS timer U2) of the second monostable multivibrator signal generator 146 are then combined through a solid state OR circuit 147 comprising a pair of IN4148 diodes D3, D4 having their cathodes tied together. In this manner, either the presence of a signal from the first signal generator 145 at the anode of the first diode D3 or the presence of a signal from the second signal generator 146 at the anode of the second diode D4 will result in the presence of a signal at the common cathodes of the diodes D3, D4, which is then fed into the output amplifier 148.

While many of the foregoing features of the signal conditioning circuit 140 as thus far described may not be required in every implementation of the present invention, the output amplifier 148, or its substantial equivalent, will generally be required for any implementation in which logical level signals will be expected to drive the electric motor 40 of the vibrating transducer 36, which will generally have a current requirement beyond the capabilities of most solid state components.

As shown in Figure 14, an exemplary output amplifier 148 comprises a 2N3904 NPN BJT transistor 142, configured as an emitter follower, coupled with a TIP42 high current PNP transistor 143 in a TO-220 heat dissipating package, for providing the necessary current for operation of the electric motor 40 of the vibrating transducer 36. The output amplifier 148 as shown may be considered a two stage, high current emitter follower.

In any case, the output from the output amplifier 148 is fed through an output power level selector 149 to an output jack 150, into which the power cord jack 127 to the electric motor 24 of the vibrating transducer 36 may be plugged. As shown in Figure 14, the output power level selector 149 preferably comprises a 22 ω resistor R8, which is selectively placed in series with the output circuit by selecting the appropriate position of a single pole, single throw switch SW2. Although Applicant has found that 22 ω is an appropriate value for the resistor R8, it is noted that the value is selected empirically in order to obtain the user desired tactile feel for the "low" output selection. Additionally, the resistor R8 may be replaced with a potentiometer, thereby providing a fully adjustable output power level.

Finally, another embodiment of a power conditioning circuit 151, such as that which is shown in Figure 15, is preferably provided to prevent and for suppress voltage spiking, such as may be expected in response to the highly inductive load typical of the type of electric motor 24 utilized in the implementation of the vibrating transducer 36. A shown in

Figure 7B, the power conditioning circuit comprises a 10 μF electrolytic capacitor Cl tying to ground the 9-V power bus from, for example, a 9-V battery BAT. The electrolytic capacitor Cl will temporarily supply additional current to the 9-V bus as may be required to compensate for transients resulting from the draw upon the output amplifier 48 caused during startup of the electric motor 24 of the vibrating transducer 36. Additionally, the power conditioning circuit preferably comprises an ON-OFF switch SWI and may also include a power on indicator 152. Such a power on indicator may be readily implemented with a 1 kω current limiting resistor Rl in series with a light emitting diode ("LED") Dl between the 9-V power bus and ground. Referring now to the figures generally, and to Figures 16A through 19B in particular, the operation of the vibrating transducer 36 of the present invention is detailed. For purposes of this exemplary discussion, it is assumed that the vibrating transducer 36 is to be used in an application requiring the differentiation of two distinct tactile stimulations. It should be recognized, however, that the vibrating transducer 36 of the present invention is readily capable of being used in applications requiring more. Still further, especially in light of this exemplary disclosure, those of ordinary skill in the art will readily recognize the necessary modifications of the previously described circuits as may be required for the implementation of higher order systems.

In any case, Figures 16A and 16B depict, in voltage time plots, representative input signals as may be produced by a signal generator 139 such as that shown in Figure 13. In particular, Figure 16A shows a "short" pulse train, approximately 3 milliseconds in duration. This pulse train may be generated by the signal generator 139 to represent a first event. Likewise, Figure 16B shows a "long" pulse train, of approximately 15 milliseconds in duration, such as also may be generated by the signal generator 139 of Figure 6. This latter pulse train may be generated to represent a second event. In operation of the vibrating transducer 20 of the present invention utilizing the signal conditioning circuit 140 of Figure 14, the pulse trains of Figures 16A and 16B will be fed in a desired pattern into the input jack 141 of the of the conditioning circuit 140 at terminal Jl-I. For example, the pulse trains may be fed in the pattern SHORT-LONG-SHORT-SHORT-SHORT-LONG. As previously described, the conditioning circuit 140 first produces the envelope of the input signal. Continuing with the example as set up, then, the output of the envelope detector 142 will be as depicted in the voltage time plot of Figure 17A representing the signal obtained at the cathode of diode D2. As shown in the plot of Figure 17A, however, the output of the envelope detector 142 will generally reflect effects of the time constant of its

capacitor C2, resulting in roll off in the waveform. In order to produce a cleaner, more square waveform (and thus more readily utilizable for controlling timing operations), the output of the envelope detector 142 is preferably passed through an input amplifier 143 configured to operate in Class C, or saturation. As depicted in Figure 17B, representing the voltage waveform at the collector of the transistor Ql forming the input amplifier 143, the output of the input amplifier 143 is a series of generally squared pulses. In any case, the input signal pattern SHORT-LONG-SHORT-SHORT-SHORT-LONG is at this point still preserved.

As also previously discussed, the next stage of the conditioning circuit 140 comprises a pair of monostable multivibrator, or "one-shot," signal generators 145, 146. The amplified signal depicted in Figure 17B is fed directly into the trigger pin 2 of the CMOS timer Ul of the first signal generator 145. Each pulse of the input signal crossing the threshold trigger level, shown as TRIG on Figure 17B, will trigger the first timer Ul, causing an approximately 10 millisecond pulse, as depicted in Figure 19 A, to be output from pin 3 of the timer Ul. It is desired, however, that only the longer pulses trigger the CMOS timer U2 of the second signal generator 146. To affect this result, then, the amplified signal of Figure 17B is first passed through a low pass filter 144 prior to application to the trigger pin 2 of the CMOS timer U2 of the second signal generator 146. As is evident from the depiction of Figure 18, representing the filtered signal output from the low pass filter 144, only the longer duration pulses are of low enough frequency to sufficiently pass the filter 144 to cross the threshold level as indicated on Figure 18 as TRIG. As a result, when this waveform is fed into the trigger pin 2 of the CMOS timer U2 of the second signal generator 146, only the longer pulses cause the generation of the approximately 40 millisecond pulse, as depicted in Figure 19B, at the output pin 3 of the CMOS timer U2 of the second signal generator 46.

The pulse trains thus generated by the pair of monostable multivibrator, or "one-shot," signal generators 145, 146 is are then combined by the solid state OR circuit 147 depicted in Figure 14. Upon combination, the following voltage pattern will be present at the input to the output amplifier 148: V ₁ Om _S -PaUSe-V ₄ Om _S -PaUSe-ViOm _S -PaUSe-V ₁ Om _S -PaUSe-V ₁ Om _S -PaUSe-V ₄ O _111S , representing a series of 40 millisecond duration and 10 millisecond duration pulses of voltage in the SHORT-LONG-SHORT-SHORT-SHORT-LONG pattern of the input signal. These voltages are then passed through the output amplifier 148, which provides sufficient current for operation of the motor 40 of the vibrating transducer 36, and then passed to motor 140 of the vibrating transducer 36, which is turned on for 10 milliseconds, turned off, turned on for 40 milliseconds, turned off, turned on for 10 milliseconds, turned off, turned on for 10 milliseconds, turned off, turned on for 10 milliseconds, turned off, and then turned on for 40

milliseconds. As has been found by Applicant, the input signal pattern is readily perceived through the vibrating transducer 36.

FIG. 20 depicts one embodiment of a digital input device 221 (which may incorporate a signal generator 23) for use either in conjunction with a base unit 20 or a transducer unit 29. Digital input device 221 has a display 222 and a user interface with tempo increase 224 and decrease 224 buttons, a beats-per-measure selection button 225, a note-value (e.g., sixteenth note, eighth note) or divisions-per-beat selection button 226, a series button 227, and a channel select button 228. Furthermore, the display 222 is adapted to provide a digital readout of the current tempo, time signature, divisional settings, and channel number. In this manner, a conductor, bandleader, or music instructor can program the digital input device 221 to produce polyrhythm timing signals, with simultaneous rhythms directed to different channels, so that one instrument section can play in accordance with one rhythm (such as a two-beat pattern) and another instrument section can play in accordance with a different rhythm (such as a three-beat pattern). Also, a series button 227 is provided so that the digital input device 221 can be programmed to produce series of different patterns of accented beats, such as a hemiola 1-2-3-1-2-3-1-2-1-2-1-2 pattern. Alternatively, the series button 227 can be used to mark different divisional patterns of a series of beats, such as two crochet notes, each representing a beat, followed by four quaver notes. In these various manners, the digital input device 221 is readily adapted to provide complex rhythms and beat patterns. Additionally, it is contemplated that the digital input device 221 may incorporate an interface (not shown), such as a MIDI interface, a USB connection or a wireless bluetooth or infrared connection, for connecting the device 221 to an external digital input source, such as a MIDI keyboard, a general purpose laptop computer, a general purpose personal digital assistant, or some other portable consumer electronics device. This would be particularly useful for programming the digital input device 221 to produce very complex rhythms such as that depicted in the upper scores of FIG. 11. Whereafter, the conductor, bandleader, music instructor, lead musician or the like need only select desired tempo and starting point to have the metronome of the present invention produce, for each musician provided with a transducer 35, rhythmic stimulation for a complete musical selection. Additionally, display 222 may be adapted to provide a graphical readout comprising a musical score, such as those shown in FIG. 11. The digital input device 221 is preferably provided with memory storage, such as flash memory, to store the various complex patterns defined or selected thereon. In this manner, the digital input device 221 is equipped to program, record, and store sequences. Although not shown in FIG. 20, the digital input

device 221 may also be provided with a speaker and an audio control button, a light indicator, and other features. The digital input device 221 may also be provided with a infrared-based remote control unit to start and stop the sequence.

It is also contemplated that the transducer units 29 worn by each musician may also incorporate a full-fledged, or scaled-down digital input device 221 so that each musician can use the metronome when practicing by herself or at home by locally defining or selecting a beat pattern. To this end, the digital input device 221 may be equipped with a switch 229 that enables the musician to select between a remote control channel, wherein the digital input device 221 receives a rhythmic pattern from an external source such as the conductor, and a local control channel, where the digital input device 221 outputs a rhythmic pattern selected by the musician using the built-in user interface.

FIG. 21 depicts an embodiment of a metronome comprising a transducer housed in a small cylinder 235, about 2-3 centimeters in length, attached to a belt clip 291. Flexible decoupling material, such as cotton, foam, or rubber, is placed between the transducer housing 235 and the clip 291 itself. The clip 291 is designed to fit on a user-selected and adjustable location on a belt 240. The transducer is intended to be worn so that the outside of the transducer housing 235 will contact the musician, preferably, at the small of the musician's back, to facilitate conduction of the vibrations through the musician's bones. Wires 242 connect the transducer to a separately housed transducer controller or driver circuit 230 that is also adjustably clipped to the belt 242, such as at the musician's side. The wires 242 are preferably partially concealed and protected within the belt 240 or placed on the inside of the belt 240, using any suitable means - such as snap loops, ties, or hook and loop material - for keeping the wires inside the belt 240 or in contact with the inside surface of the belt 240, while still facilitating the adjustable positioning of the transducer housing 235 and transducer controller or driver circuit 230. It will be understood that the clip 291 may be replaced with any other suitable means for removably attaching the transducer housing 235 to the belt 240.

FIG. 22 shows, in perspective view, an embodiment of a metronome comprising a different type of contact device 14. Contact device 14 comprises an ankle strap 12 for connecting a tactile transducer 13 to a musician's ankle bone (either the medial malleolus of the tibia or the lateral malleolus of the fibula) or shin (tibia) bone. Electrical cable 242 connect a separately-housed signal and power source 11 for the tactile transducer 13. The ankle strap 12 may comprise releasably engageable hook and loop type fasteners, such as are commercially available under the well-known trademark "VELCRO," or any other

substantially equivalent fastener system, for snuggly securing the strap 22 about the user's ankle. As shown in FIG. 22, a musician 18 affixes the transducer 13 in a minimally obtrusive location utilizing the strap 12. The musician then connects the electrical cable 242 between the contact device 14 and the signal and power source 11 by inserting a standard plug (not shown) into the output jack (not shown) of the signal and power source 11. Other embodiments for connecting a contact device 41 to other locations on a musician's body — such as the musician's ankle, chest, knee, or elbow - will also fall within the scope of the of the invention.

While the foregoing description is exemplary of the preferred embodiment of the present invention, those of ordinary skill in the relevant arts will recognize the many variations, alterations, modifications, substitutions and the like as are readily possible, especially in light of this description, the accompanying drawings and claims drawn thereto. For example, with sacrifice of the benefits described herein with respect to the preferred embodiment of the tactile vibrating transducer 36, the transducers 35 of the multiple channel metronome 15 of the present invention may be implemented as a piezoelectric device, buzzer, pair of electrodes, a bone density resonator, an electrical stimulation device, a mechanical transducer, an eccentric motion generator, an audible device or any other substantially equivalent structure capable of imparting the desired tactile stimulation. Additionally, the metronome 15 of the present invention may find particular utility in circumstances where a split performance group is led by multiple conductors. In this case, the conductors, rather than individual musicians, may each be provided with a transducer 35 for receiving appropriately staggered timing signals. Still further, the sound timer 70 may be implemented as an integral unit with the base unit 20 of the metronome 15 or as a separate device. In any case, because the scope of the present invention is much broader than any particular embodiment, the foregoing detailed description should not be construed as a limitation of the scope of the present invention, which is limited only by the claims appended hereto.