BACKGROUND OF THE INVENTION: In conventional spatial hearing the phase difference of incoming sound waves to the left ear canal and the right ear canal are evaluated to obtain sufficient spatial information.

Whole body spatial listening or holistic spatial listening should be understood as a composition of conventional spatial hearing and whole body perception of sound waves which are transmitted through the skin, the largest perceptive organ of the human body. Dominant skin receptors for sound perception are known as Meissner Cells with a maximum sensitivity at a frequency about 30 Hz and the Pacini cells with a maximum sensitivity at a frequency of about 300 Hz. Meissner Cells are located on skin which are not covered with hair and Pacini cells are located on skin covered with hair.

The invention provides a simple and affordable moving sound amplifier, either integrated in a surround system or to be used separately, with inputs from audio equipments, video equipments and vocal or instrumental live inputs from karaoke microphone. Circular movement or linear movement of sound can be achieved during playing the music or sounds through electronic control of every speaker. The number of speakers used are preferably 2,4, 6, 8,12, 16.... n. Because the number of speakers determines the factory price of the moving sound amplifier, moving sound amplifier with a 4-speaker-set- up is taken as a prefered device.

Dolby-and other surround modes support whole body perception similar to the moving sound amplifier according to the invention. However Dolby surround technology is primarily a front-oriented recording technology and the surround sound movement is fixed during recording. A special player is needed to play the recording as well as a set of specialised speakers.

The moving sound effect from the moving sound amplifier according to the invention is not front-oriented with regard to a TV-display or a"virtual stage". It does not need a special player and any acoustical input is suitable.

The effect is not realised on the recording level but by modulating the output signals.

- In our experience a smooth and harmonica (circular or linear) movement is necessary for meditative listening. For this key-application the moving sound amplifier needs n identical speakers. For an integration of the moving sound amplifier according to the invention into a surround system, the speaker-set must be modified such that in case of a 5. 1-channel-DVD equipment the 4 corner speakers should be identical.

OBJECT OF THE INVENTION: The main object of the invention is to provide a moving sound amplifier for amplification and providing audio inputs to a plurality of identical loudspeakers located at desired locations in a listening room. The moving sound amplifier moves the sound from speaker to speaker in the chosen chain of speakers.

The sound waves from the loudspeakers may be moved in circles, both clockwise and counterclockwise. They may also be moved linearly forward and backward.

In general the audio-input-signal is modulated by an oscillation, produced by a function generator. The number of channels required in the function generator is the same as the number of loudspeakers used with the amplifier.

A power amplifier pack containing same number of power amplifiers as the number of loudspeakers is used.

If the number of speakers is small enough (2,4 or 6 speakers) the oscillation can be realised as a sine-wave-function or a triangular wave function. For a larger number of speakers (6, 8 or more) only triangular wave functions are suitable. In this case sine wave functions do not produce sufficient smoothness of the sound movement.

The moving sound effect is obtained by maintaining a phase difference between each successive channel. If only two power amplifiers and two loudspeakers are used, the phase difference between the two modulator signal channels will be 180°. When a 4 channel modulating signal and 4 loudspeakers with respective power amplifiers are used, the phase difference between each modulating signal channel will be 90°. Similarly if N number of loudspeakers are used with respective power amplifiers the phase difference between each successive channel will be 360°/N. The movement of sound will be smoother if the number of speakers and respective power amplifiers are increased. The multichannel outputs from a function generator with required phase shift are achieved using conventional phase shifting networks.

BRIEF DESCRIPTION OF THE FIGURES: Fig. 1A shows circular motion of sound in a listening room with four speakers using signals from a 4-channel wave generator.

Fig. 1B shows linear motion of sound in a listening room with four speakers using signals of a 2-channel wave generator.

Fig. 1C shows the circular sound mode as realised with the moving sound amplifier according to the invention.

Fig. 2A shows the output signals (S1, S2) of a 2-channel sine wave signal generator, having a phase difference of 180°.

Fig. 2B shows the output signals (S1, S2) of a 2-channel triangular wave signal generator, having a phase difference of 180°.

Fig. 3A shows 50% clipped output signals (S1-S4) from a 4-channel sine wave generator.

Fig. 3B shows 50% clipped output signals (S 1-S4) from a 4-channel triangular wave signal generator.

Fig. 4 shows 75% clipped output signals (S1-S8) from a 8-channel triangular wave signal generator.

Fig. 5 shows the output signals (SI, S2) from a 2-channel sine wave signal generator having 180° phase difference between each channel using the complete signals.

Fig. 6 shows the output signals (S1-S4) from a 4-channel sine wave generator, with 90° phase difference between sucessive channels using 50% clipped signals.

Fig. 7A shows sine wave signals (S1-S8) with an 8 channel sine wave signal generator.

Fig. 7B shows triangular wave signals (Sl-S8) withan8channel triangular wave signal generator.

Fig. 8 shows a schematic circuit diagram of a prefered moving sound amplifier according to the invention with four identical loud speakers, combined with a centre speaker and a subwoofer for 5.1-surround-sound application.

DESCRIPTION WITH REFEENCE TO THE FIGURES: In the listining room shown in figure 1A the direction of motion of the sound may be clockwise or counter clock-wise as shown. Similarly in the listening room shown in figure 1B, the direction of motion of the sound may be forward or backward as shown.

In the listening room shown in figure 1C always two neighbouring speakers such as LI and L2 are active. Selecting a clockwise direction of the sound movement at the beginning, the volume of speaker LI is set to its maximum and the volume of speaker L2 to its minimum. At this moment predominately the wavefront from LI marked as trace Tl is touching the human body. Depending on the selected speed of the circular mode, when the volume of LI is decreased slowly and the volume of L2 is increased slowly the wavefront touching the human body moves from trace T, to trace T2. At trace T2 the volumes of LI and L2 may be balanced and for further sound movement, the volume of L2 may be increased further and that of LI may be decreased up to their respective minimum. Then at trace T3 of the wavefront arising from L2 will be perceived by the human body predominantly. Same procedure for the ongoing sound movement from L2 to L3, from L3 to L4 and from L4 to L1, may be followed when one full circle is completed. Same procedure is used for the counterclockwise circular movement between speakers L 1-L4-L3-L2-L 1. A comparison of figures 7 A and 7B reveals that in the case of larger number of speakers for controlling the circular movement, triangular waves are better than sine wave functions. In both cases only 25% of the signals are used for modulating the audio-signal and 75% are clipped.

Fig. 7A shows S1-S8 sine wave functions. The used part of the sine wave gets more and more flat. That means during the sound movement, pinpointing of the sound gets diffuse and constant speed of the movement can no longer be achieved with sine wave functions.

Fig. 7B shows S1-S8 triangular wave functions. The used part of the triangular wave does not change its shape. It is always a triangle with a distinct peak, which produce a steady and clear sound movement.

Figure 8 shows a schematic diagram of a prefered moving sound amplifier according to the invention. The moving sound amplifier according to the invention essentially comprises a pre-amplifier (1) and a multi-channel signal generator (2,3) with multiple channel outputs having a phase difference between sucessive channel outputs for modulating the input audio signal received by the pre-amplifier (1). The audio signal is modulated with the multiple channel modulating signal from the signal generator (2,3) in a mixer (8) to obtain a set of audio signals with phase angle shifted in accordance with the phase shift between the output channels of the signal generator.

A 4-channel sine wave generator (2) with the signals A, B, C, D similar to signals S1-S4 shown in figure 3A and a 2-channel triangular wave, generator (3) with the signals E, F similar to signals S 1, S2 shown in figure 2B. Because these signals are used in a 4 speaker-system, they are doubled (E, E, F, F) and fed to respective 2 speakers.

These audio signals are amplified by a power amplifier pack (10) containing individual power amplifiers (P1, P2, P3, P4...) feeding to the set of loud speakers (11) located in the listening room. By placing the loud speakers (Li, L2, L3, L4,...) at appropriate locations with respect to where the listener is located, moving sound is perceived by the listener.

The signal generator may be a sine wave generator (2) or a triangular wave generator (3) or both. A circular/linear selector switch (5) is used to select different movements of sound. If only one generator is used, switch (5) may be used to select different movements of sound. These circular movement is based on 4 channels with 90° phase shift. Linear movement is based on 2 channels using 180° phase shift. A clockwise/counterclockwise selector switch (4) is also provided to select the direction of motion of sound. The multi-channel modulating signal is fed to a mixer (8) through a sound movement actuator-switch (6) which can stop the movement of sound or start the movement of sound as desired by the listener. If moving sound mode is not used, the listener can listen to normal stereo or surround-sound music or to the TV-or video sound.

An LED display (7) is provided for displaying the active phases of the oscillator (A, B, C, D,...) in relation to the loud speakers (Li. L2, L3, L4...). The display will also provide indication of stopping and starting the movement of sound.

The speed of movement of sound will depend upon the frequency of the modulating signal. Therefore the signal generators are provided with continously variable frequency. The frequency range of the modulating signal are preferable from 0,01 Hz to about 1 Hz. The output from the 4 channel signal generator (2) are clipped to have only +ve values before it is fed to the mixer (8). The modulated signals from the mixer is fed through a stereo/cinema selector switch (9), which is only actuated when the movement sound actuating switch (6) is in off position. In this case the listener can choose between stereo or dolby surround music, using 2 to 6 of the speakers and respective Power amplifiers (P). If the sound movement actuator is on position, the 4 signals A, B, C, D or respective E, E, F, F are fed to the 4 power amplifiers Pl-P4 and speakers LI-L4. Each signal channel is connected through a separate power amplifier (Pl, P2, P3, P4...) with independent volume controls (Vl, V2, V3, V4...). A stereo/mono selector switch (12) and a master volume control (13) are connected between the stereo/cinema selector switch (9) and the pre-amplifier (1). A tone control (14) is provided for treble/bass control of the output audio signal. The signal generators (2,3) are provided with a speed control (S).

A remote control (15) is preferred for easily operating the controls of the amplifier. A karaoke amplifier (16) and microphone (17) may be connected to the pre-amplifier (1) for live performance.

Moving sound according to the invention could be seen as a special effect, to be combined with all other effects of well-known amplifiers, such as stereo, dolby surround or quadro or other surround systems in an affordable amplifier. Such an amplifier can be readily used by individual listeners at their home. It can also be effectively used for music meditation. Places such as beauty parlours, discotheques, hotel rooms and marriage-halls or sport- studios can use the moving sound amplifier to provide quality listening of music with this special effect for animation or relaxation.

Combined with karaoke-systems it could be used as special effect in any place of live-performances such as karaoke-bars, schools & kindergartens.