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Title:
A METHOD FOR MONITORING ELECTRO-ACOUSTIC PERFORMANCE OF A HEARING DEVICE AND HEARING DEVICE
Document Type and Number:
WIPO Patent Application WO/2018/103899
Kind Code:
A1
Abstract:
The invention is directed to a method for monitoring electro-acoustic performance of an electro-acoustic hearing device (1) that comprises an output transducer (5) emitting a vibration based output signal. According to the method a measure is detected that is characteristic for a vibration of the transducer (5) caused by emission of sound by means of a vibration sensitive sensor (8) that is directly or indirectly coupled with the receiver (5). Furthermore, the measure is compared with a reference measure, and an action is taken if the measure exceeds the reference measure.

Inventors:
MEISTER BERND (DE)
TAGHAVI HAMIDREZA (NL)
VAN HALTEREN AART Z (NL)
Application Number:
PCT/EP2017/059441
Publication Date:
June 14, 2018
Filing Date:
April 20, 2017
Export Citation:
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Assignee:
SIVANTOS PTE LTD (SG)
SONION NEDERLAND BV (NL)
MEISTER BERND (DE)
TAGHAVI HAMIDREZA (NL)
VAN HALTEREN AART Z (NL)
International Classes:
H04R25/00
Foreign References:
EP2640095A12013-09-18
EP2104376A22009-09-23
EP2061274A12009-05-20
EP2966881A12016-01-13
EP2677770A12013-12-25
Other References:
None
Attorney, Agent or Firm:
FDST PATENTANWÄLTE (DE)
Download PDF:
Claims:
Claims A method for monitoring electro-acoustic performance of a hearing device (1 ) that comprises an output transducer (5) emitting a vibration based output signal, comprising the steps of

- detecting by means of a vibration sensitive sensor (8) a measure that is characteristic for a vibration of the output transducer (5) caused by emission of sound, the vibration sensitive sensor (8) being directly or indirectly coupled with the output transducer (5),

- taking account of the measure as a pre-conditioned measure in a feedback suppression,

- using the measure to check the function of the microphone (3),

- deriving from the measure information regarding a distortion of the acoustic emission of the output transducer (5),

- detecting the measure when the hearing device (1 ) is in an unused state and/or when the hearing device (1 ) is positioned in an intended wearing position,

- comparing the measure with a reference measure,

- determining on the basis of the comparison information about the type of the output transducer (5),

- taking an action if the measure exceeds the reference measure,

- using a receiver (5) as the output transducer,

- using the measure as a criterion for an at least partial occlusion of a sound output opening (9), and, as an action, issuing a warning regarding the occlusion of the sound output opening (9),

- having a cerumen guard (7) assigned to the output transducer (5), and as an action issuing an instruction to change the cerumen guard (7),

- deriving from the measure information that indicates a changing of the cerumen guard (7), and afterwards detecting the measure anew,

- after detecting the changing of the cerumen guard (7) calibrating the reference measure, - comparing the measure with a reference measure that is indicative for a fit of an earpiece (7) in the ear canal, the earpiece (7) supporting the receiver (5), and

- taking an action if the measure exceeds the reference measure, wherein the action is issuing an instruction to correct the fit of the earpiece (7) in the ear canal.

2. A method for monitoring electro-acoustic performance of a hearing device (1 ) that comprises an output transducer (5) emitting a vibration based output signal, comprising the steps of

- detecting by means of a vibration sensitive sensor (8) a measure that is characteristic for a vibration of the output transducer (5) caused by emission of sound, the vibration sensitive sensor (8) being directly or indirectly coupled with the output transducer (5),

- comparing the measure with a reference measure, and

- taking an action if the measure exceeds the reference measure.

3. The method according to claim 1 or 2, comprising the step of

determining the reference measure in a calibration step prior to or during a first use of the hearing device (1 ).

4. The method according to one of claims 1 to 3, comprising the step of

detecting the measure, preferably in predetermined temporal intervals, when the hearing device (1 ) is positioned in an intended wearing position.

5. The method according to one of claims 1 to 4, comprising the step of

detecting the measure when the hearing device (1 ) is in an unused state, especially when the output transducer (5) is positioned outside of the ear canal.

6. The method according to one of claims 1 to 5, comprising the step of

using a receiver (5) as the output transducer.

7. The method according to claim 6, comprising the steps of using the measure as a criterion for an at least partial occlusion of a sound output opening (9), and, as an action, issuing a warning regarding the occlusion of the sound output opening (9).

8. The method according to one of claims 1 to 7, comprising

a cerumen guard (7) assigned to the output transducer (5), and as an action issuing an instruction to change the cerumen guard (7).

9. The method according to claim 8, comprising the steps of

deriving from the measure information that indicates a changing of the cerumen guard (7), and afterwards detecting the measure anew.

10. The method according to one of claims 6 to 9, comprising the step of

after detecting the changing of the cerumen guard (7) calibrating the reference measure.

1 1 . A method, preferably according to one of claims 1 to 10, for monitoring electro-acoustic performance of a hearing device (1 ) that comprises, as an output transducer, a receiver (5), comprising the steps of

- detecting by means of a vibration sensitive sensor (8) a measure that is characteristic for a vibration of the output transducer (5) caused by emission of sound, the vibration sensitive sensor (8) being directly or indirectly coupled with the output transducer (5), and

- taking account of the measure as a pre-conditioned measure in a feedback suppression.

12. A method, preferably according to one of claims 1 to 1 1 , for monitoring electro-acoustic performance of a hearing device (1 ) that comprises a microphone (3) and, as an output transducer, a receiver (5), comprising the steps of

- detecting by means of a vibration sensitive sensor (8) a measure that is characteristic for a vibration of the output transducer (5) caused by emis- sion of sound, the vibration sensitive sensor (8) being directly or indirectly coupled with the output transducer (5), and

- using the measure to check the function of the microphone (3).

13. The method according to one of claims 1 to 12, comprising the step of

deriving from the measure information regarding a distortion of the acoustic emission of the receiver (5).

14. A method, preferably according to one of claims 1 to 13, for monitoring electro-acoustic performance of a hearing device (1 ) that comprises, as an output transducer, a receiver (5), comprising the steps of

- detecting by means of a vibration sensitive sensor (8) a measure that is characteristic for a vibration of the output transducer (5) caused by emission of sound, the vibration sensitive sensor (8) being directly or indirectly coupled with the output transducer (5),

- comparing the measure with a reference measure that is indicative for a fit of an earpiece (7) in the ear canal, the earpiece (7) supporting the receiver (5), and

- taking an action if the measure exceeds the reference measure, wherein the action is issuing an instruction to correct the fit of the earpiece (7) in the ear canal.

15. A method, preferably according to one of claims 1 to 14, for monitoring electro-acoustic performance of a hearing device (1 ) that comprises, as an output transducer, a receiver (5), comprising the steps of

- detecting by means of a vibration sensitive sensor (8) a measure that is characteristic for a vibration of the output transducer (5) caused by emission of sound, the vibration sensitive sensor (8) being directly or indirectly coupled with the output transducer (5),

- comparing the measure with a reference measure, and

- determining on the basis of the comparison information about the type of the receiver (5).

16. A hearing device (1 ), comprising

- an output transducer (5) emitting a vibration based output signal,

- a vibration sensitive sensor (8) that is directly or indirectly coupled with the transducer (5), and

- a signal processor (4) adapted to execute the method according to one of claims 1 to 15.

17. The hearing device (1 ) according to claim 16, wherein

the output transducer is a receiver (5), and the vibration sensitive sensor (8) is attached to the outside of a receiver housing (70) of the receiver (5).

18. The hearing device (1 ) according to claim 16, wherein

the output transducer is a receiver (5), and the vibration sensitive sensor (8) is positioned on the inside of a receiver housing (70) of the receiver (5).

19. The hearing device (1 ) according to claim 16, wherein

the output transducer is a receiver (5), and the vibration sensitive sensor (8) is attached to an earpiece (7) with small distance to the receiver housing (70), the earpiece (7) supporting the receiver (5).

20. The hearing device (1 ) according to one of claims 16 to 19, wherein

- the output transducer is a receiver (5),

- the receiver (5) is designed as a double receiver having two membranes that in normal operation vibrate symmetrically opposed,

- one sound output opening (9) is assigned to both membranes, and

- the vibration sensitive sensor (8) is aligned in respect to the receiver (5) with a sensing direction (80) being directed in a direction of the planes of the membranes.

21 . The hearing device (1 ) according to one of claims 16 to 19, wherein

- the output transducer is a receiver (5),

- the receiver (5) is designed as a double receiver having two membranes that in normal operation vibrate symmetrically opposed, - one sound output opening (9) is assigned to each of the membranes.

The hearing device (1 ) according to one of claims 16 to 21 , wherein the vibration sensitive sensor (8) is connected to a feedback filter.

Description:
Specification

A method for monitoring electro-acoustic performance of a hearing device and hearing device

The invention is directed to a method for monitoring electro-acoustic performance of a hearing device. Additionally the invention is directed to such a hearing device, preferably to a hearing device adapted to perform the aforementioned method.

In the following an (especially electro-acoustic) hearing device is perceived as being a device that provides acoustic output signals to a user. Such a hearing device comprises therefore particularly a receiver (also denoted as ..speaker") that in general resembles an electro-acoustic transducer. Such a receiver is usually adapted to transform electric signals into acoustic signals, i.e. into sound waves. Alternatively, such a hearing device comprises a transducer that is adapted to convert the electric signals for providing acoustic information to the ear of a user into mechanical vibration that is transmitted by way of bone conduction to the ear.

With regard to the invention hearing devices are preferably characterized by that they are to be worn in the region of the ears of the user, for example at or even in the ear canal. Particularly, such hearing devices resemble earphones, headsets, hearables (wireless earphones or earphones with more functions than mere sound output) or hearing assistance devices (for example hearing aids). Hearing assistance devices usually are used to allow for at least a partial compensation for a reduced hearing (i.e. a hearing loss) of a person. Further, such a hearing device can resemble a tinnitus masker that outputs a noise signal that is used for therapeutic masking of an ear noise that is individual to a patient. In view of an as undisturbed as possible sound emission and of an as little lossy as possible sound transmission to the ear, a sound output port of the receivers of such hearing devices are to be worn with as little distance as possible to the ear canal or even in the ear canal. Regularly, in the ear canal there is production of cerumen (or: ear wax). Since sound transmission from the receiver to the ear drum is due to movement of air there between, there has to be a passage open for air between the receiver and the ear drum. However, the receiver is usually located inside a housing for (mechanical) protection and, therefore, the housing has to have a canal or sound output opening for the sound emitted by the receiver. That sound output opening is prone to clogging with cerumen. The period until the sound output port is completely blocked by cerumen depends on frequency and duration of use as well as on the individual tendency to produce more or less cerumen. As it can be seen, clogging causes an unwanted degradation of the electro-acoustic performance of the receiver, particularly an attenuated emission of sound.

In order to prevent or at least to slow up the clogging of the sound output opening or even of the output port of the receiver itself hearing devices often comprise a cerumen guard. Such cerumen guard (or: wax filter) is usually resembled by a thin net, sieve or something comparable. However, such cerumen guard can also be blocked by cerumen and, thus, causes attenuation of the sound emission. On the other hand, such cerumen guard enables a reduction of the risk of a clogging of the receiver itself.

Since clogging of the cerumen guard or of the sound output opening is a user- dependent slow process, the variation of the electro-acoustic performance of the receiver caused by the clogging is mostly only hardly recognizable for a user. Regularly a blocking is recognized only at a level where virtually no sound is emitted to the ear. In that case, the user has already used his hearing device for some time during which the hearing device did not comply with its specifications. Especially with respect to infants that are not yet able to enunciate sufficiently an external, preferably optical control (for example by the parents) regarding a possible obstruction of the sound output opening is necessary. However, since production of cerumen is varying between individuals even a guideline with intervals for controlling or changing of the cerumen guard cannot preclude a blocking of the cerumen guard with sufficient probability.

The invention is based upon the problem to enable a better hearing device.

That problem is solved according to the invention by a method for monitoring electro-acoustic performance of a hearing device comprising the features of claim 1 . Furthermore, the problem is solved according to the invention by a hearing device comprising the features of claim 16. Additional expedient embodiments that themselves can be a respective separate invention as well as further developments of the invention are described in the dependent claims and in the following specification.

The method according to the invention makes up for monitoring electro-acoustic performance of a hearing device (especially an electro-acoustic hearing device). Such a hearing device comprises an output transducer (i.e. preferably at least one) emitting a vibration based signal.

By executing the method according to the invention a measure is determined by means of a vibration sensitive sensor, the measure being characteristic for a vibration caused by the emission of a sound signal of the (output) transducer and the vibration sensitive sensor being indirectly or directly coupled to the transducer. "Indirectly coupled" is to be understood that the sensor is aligned in respect to the transducer with a distance being insignificant in respect to the overall size of the hearing device. The determined measure is being compared with a reference measure and, in the case of the measure exceeding or overshooting the reference measure, an action is taken.

Here and in the following "characteristic" is to be understood such that the measure provides quantitative information about at least one property of the vibration, preferably about its frequency and/or its amplitude. Thus, the vibration or its respective property can be read out of the measure distinctly. Hereby, the measure can constitute the respective property of the vibration directly. Otherwise, the measure can also be directly or indirectly proportional to the respective property of the vibration. Also, the respective property can be derived from the measure by way of a non-linear function, for example a logarithmic, an exponential or a polynomial (i.e. square, cubic, etc.) function.

The term "exceeding" or "overshooting the reference measure" is to be understood here and in the following as being directional in the sense that a difference of the measure (or its change in time) and the reference measure changes its algebraic sign. Thus, dependent on the definition of the measure the overshooting of the respective reference measure can be positively (in the sense of a real overshooting by which the measure gets greater than the reference measure) or negative (in the sense of a short fall by which the measure gets smaller than the reference measure). Preferably, the action is taken especially for that case when the measure overshoots the reference measure by a predefined rate. The predefined rate constitutes some kind of threshold or limit value that has to be trespassed for triggering the action. In that case, it is especially checked whether the difference of the measure and the reference measure exceeds or overshoots that threshold-of limit value.

Here and in the following, the term "electro-acoustic performance" of the (overall) hearing device describes especially those characteristics that can be detected during a (bidirectional - i.e. at the input or the output side) conversion between electric signals and (especially) non-electric signals, the latter transporting acoustic information. Preferably those "non-electric" signals are resembled by airborne sound. Likewise, those non-electric signals can comprise also structure-borne sound signals, i.e. signals based on mechanical vibration.

Consequently, the transducer emitting the vibration based signal is preferably constituted by a receiver that is, in an optional embodiment, to be worn at or inside an ear canal of a user. Such a receiver is - as is known - furnished to convert an electric (audio) signal into a vibration of an air column resting against the receiver, i.e. to convert the signal into airborne sound. Alternatively, the transducer can be resembled by a so called bone conduction speaker that converts the electric (audio) signal into a (especially mechanic) vibration and delivers that vibration to a cranial bone of the user. By way of bone conduction the vibration gets from that cranial bone to the middle ear and/or to the inner ear where it is "heard" in a way comparable to airborne sound.

The expression "and/or" is to be understood to mean a real combination or an alternative use of the features connected by that expression.

Preferably, the vibration of the transducer itself or for example of a housing supporting the transducer (especially an earpiece) is determined by means of the vibration sensitive sensor. Hereby, especially a transfer function of the transducer is determined since the vibration detectible by means of the sensor is related to the vibrational (for example acoustic) output of the transducer. I.e. the measure provides also information about the electro-acoustic performance (or characteristics) of the receiver or the electro-mechanic performance of the bone conduction speaker. Recognizably, those electro-acoustic or electro-mechanic characteristics are influenced by intrinsic features of the transducer itself as well as by the suspension of such a transducer in a housing of the hearing device, for example in the earpiece described above. Preferentially, as the measure a frequency response of the transducer is determined. In that case, especially a vibration spectrum is derived from the measuring signal output by the vibration sensitive sensor.

By means of the vibration sensitive sensor, it is therefore possible to monitor the electro-acoustic performance of the whole hearing device, particularly of the transducer, and to take a corresponding action, for example to issue a corresponding warning, in the case that the electro-acoustic performance does not or no longer comply with the specifications. Expediently, the monitoring of the electro-acoustic performance of the hearing device can thus be carried out by the hearing device itself, preferably automatically, and therefore does no longer fall to the user of the hearing device (alone). Regularly, due to a familiarization the user is not able to clearly recognize changes of the electro-acoustic performance that progress slowly. Rather, he realizes such changes not until a degree of change at which the user has had to accept significantly changed electro-acoustic performance for a needless long time. In such a case, the user of especially a hearing assistance device has not had a sufficient provision for his hearing, in the worst case.

According to an expedient embodiment of the method, the reference measure is determined in a calibration step prior to or during the first usage of the hearing device. Thus, the reference measure can be adjusted especially to the individual design of the hearing device, for example to an individually used earpiece that supports the transducer, for example the receiver. Because recognizably, the transfer function of the transducer, especially the measure detected by the vibration sensitive sensor, varies in dependence on an acoustic coupling of the transducer (and of the sensor) to the environment. I.e. the transfer function can vary especially in correspondence to the composition, for example the hardness, of a material of the housing, especially of the earpiece. In the last case such individually manufactured earpieces (so called earmolds) are often made out of a comparably stiff plastic (for example an acrylic), whereas standard earpieces that are provided in different sizes are mostly made of a soft plastic (for example a silicone) such that they adapt better to the ear canal of a plurality of users. Furthermore, the transfer function of especially the receiver can vary in dependence on the position and on the acoustic coupling of the receiver and/or of the probably present earpiece in the ear canal.

According to an alternative embodiment of the method which falls into the scope of the invention, the reference measure is made up especially by a measure which is deposited in a storage module of the hearing device - in that case the reference measure is especially stored as a factory setting. According to an optional embodiment such stored reference measure is overwritten during an individual calibration as mentioned before.

According to an expedient embodiment of the method, the measure is determined especially when the hearing device is aligned in its intended wearing position. Especially in the case that the transducer is constituted by the receiver which is to be worn at or in the ear canal that measure is thus determined not before the receiver is aligned at or in the ear canal. Preferably, in that case the measure is determined continuously or in prescribed time steps (also named as interval) while the hearing device is worn as intended. Thus, especially during the intended use of the hearing device, the electro-acoustic performance of the transducer can be monitored by intervals that are short especially in comparison to a (probably daily) period of use. According to that embodiment, a calibration or a first determination of the reference measure is preferably conducted at the first use of the hearing device - i.e. especially during wearing the hearing device at or in the ear or, in the case of a hearing assistance device, during a so called adaption to the user, more precisely to his ear.

According to a further expedient embodiment of the method which is especially alternative to the aforementioned embodiment, the measure is determined when the transducer is aligned outside of the ear canal. That means that the measure is especially determined when the hearing device is not worn or not used as intended, rather, when the hearing device is especially taken off. Thus, in that case probably the earpiece supporting the transducer is also not aligned in the ear canal. Preferably, in that case a test signal is output by means of the transducer and the measure, especially the frequency response of the transducer, is determined on the basis of the test signal. The advantage of that embodiment is that the vibration pattern of the transducer is not influenced by the alignment of the transducer, especially of the earpiece, inside of the ear canal. Consequently, such influences by the ear and/or the ear canal of the user can be disregarded. Hence, a calibration of the reference measure while the hearing device is aligned in its intended wearing position (especially in the ear canal) can be omitted, as well. For example, the determination of the measure is conducted when due to a movement of the hearing device - recognized for example by means of a movement sensor - it is realized that the hearing device is taken off. Alternatively, the determination of the measure is conducted during a shutdown process of the hearing device.

According to a preferred embodiment of the method, especially in the case that the transducer is a receiver, the (vibration) measure is taken as a criterion for an at least partly occlusion of a sound output opening of the hearing device. In the intended wearing position, that sound output opening is expediently directed to the eardrum and preferably aligned inside the ear canal. Hereby, as an action a warning about the occlusion of the sound output opening is issued. I.e. based on the measure it is determined whether airborne sound output by the receiver can exit unobstructed. In other words, the measure is taken as an indicator whether the user can hear sufficiently with the hearing device or whether he just gets no sound or sound that is attenuated in an undesirable way by the hearing device. Recognizably, by occlusion of the sound output opening the vibration pattern of the receiver detected by the vibration sensitive sensor changes when the receiver or the sound output opening assigned to that receiver is obstructed. For example, due to such occlusion, the (resonance) frequency detected by means of the sensor moves to another frequency and/or an amplitude differing from the reference is determined. That embodiment of the method can be applied to hearing devices with receivers being positioned especially in the ear canal during intendent use as well as to hearing devices with receivers during intendent use being aligned outside the ear canal and coupled to the ear canal by a sound tube. In the last case, the influence of a comparably large air volume between the eardrum and the sound port of the receiver itself is considered for the comparison of the measure with the reference measure or at least during calibration of the reference measure, expediently.

In dependence on the type of construction of the hearing device, the aforesaid sound output opening can be constituted especially by a sound port of the receiver itself (also named as sound socked or receiver sprout) as well as by an exit opening of a sound canal leading especially through the aforementioned earpiece.

As a criterion, especially as the aforesaid threshold or limit value for distinguishing undesirable or especially impermissible deviation of the measure from the reference measure, preferably a value between one and ten decibel, especially below about five decibel is chosen. According to an expedient embodiment of the method wherein the hearing device comprises a cerumen guard assigned to the receiver, the action to be taken is preferably constituted by issuing an instruction to change the cerumen guard. That instruction is output for example acoustically, i.e. especially by means of the receiver itself. Alternatively or in an optional embodiment additionally, the instruction is issued by means of an optical display that is assigned to a control device (for example a remote control) that is assigned to the hearing device separately. The cerumen guard is especially constituted by an element that is positioned in the sound output opening and serves to prevent intrusion of cerumen into the sound canal or into the receiver itself. Preferably, the cerumen guard is made up by a kind of mesh, sieve or membrane that is permeable to airborne sound. According to an optional embodiment, the cerumen guard can also be an especially one piece (monolithic) part of a standard earpiece (often also named as "ear dome"). Therefore, in the last case the whole standard earpiece has to be changed.

The aforesaid embodiment is especially beneficial since the production of cerumen inside the ear canal varies between individuals and, therefore, a cleaning or a change of the cerumen guard in (fixedly) prescribed intervals is little productive. Furthermore, cerumen is a regular reason for occlusion (here also referred to as "clogging") of the sound output opening of the hearing device. Such clogging mostly proceeds with especially individually different rates. Therefore, there can be provision of a sound output with little variation of the transfer function of the receiver in a simple way especially for users who rarely can enunciate and/or are comparably little sensitive to changes of the electro-acoustic performance of the hearing device.

According to a further expedient embodiment of the method, information indicating a change of the cerumen guard is derived from the measure determined by means of the vibration sensitive sensor. For example, by means of the sensor a clicking or snapping sound being characteristic for the change of the cerumen guard, especially for a putting on or a putting in of the cerumen guard is detected. Thereupon, the measure being characteristic for the vibration of the receiver is determined anew, for example by means of emitting an acoustic test signal by the receiver, for the checkup whether the cerumen guard has been changed, actually. If a new or cleaned cerumen guard has been applied, according to an optional embodiment, a skip can be detected in the vibration spectrum in comparison to the preceding measurements. For this purpose, at least the preceding measurement result is stored, preferably. However, in each case the measure will not overshoot the reference measure after a change of the cerumen guard. However, if still no change of the vibration spectrum, for example of the frequency response, is detected (in particular if still an overshoot of the reference measure is detected) preferably a new instruction to change the cerumen guard is issued. According to a further optional embodiment, in that case a confirmation by the user is requested, additionally. Such a confirmation can be conducted by triggering a prescribed switch. According to an expedient development of the method, a repeated issuing of the instruction to change the cerumen guard within a prescribed time window (for example 15 minutes or up to one hour) is taken as an indicator for a defect of the receiver. Accordingly, corresponding information is output.

According to an alternative or optionally additional embodiment of the method, the aforesaid threshold or limit value is considered especially for detection of the (at least partly) clogging of the sound output opening. Additionally, a second, especially in view of the aforesaid "first" limit value more coarse or higher limit value is stored wherein the transgression of such second limit value is considered as an indicator for a defect of the receiver. Because, recognizably a defect of the receiver causes a more significant (i.e. more severe) change of the vibration pattern in respect to the reference in comparison to an especially just partly clogging of the sound output opening. Additionally, in the case that no signal is detected or output by the sensor it can be taken as an indicator for a defect of the sensor itself.

According to a beneficial embodiment of the method, subsequent to the change of the cerumen guard a calibration of the reference measure is conducted preferably automated. That embodiment is expedient especially in the case that the change of the cerumen guard is detected automatically (as described before) and that preferably the change of the cerumen guard has been confirmed in a verification step subsequent to the detection of the change. That verification step may be re- sembled as described before by determining the vibration measure a new. Hereby, it is possible, to adapt the reference measure automated to characteristics of the cerumen guard that have been changed, for example to the "new" characteristics of an ear dome with an integrated cerumen guard that has been changed in regard to the previous used ear dome. In that case, during the verification step it is expediently confirmed at first that there is no more clogging of the sound output opening and that the electro-acoustic performance is located in a target area lying between predefined limits. Thus, the above described subsequent new calibration of the reference measure makes it possible to subsequently determine the frequency response in an especially precise way with regard to the respectively applied cerumen guard.

According to an expedient embodiment of the method that also constitutes an invention for itself, the measure being characteristic for the vibration of the transducer, especially of the receiver, is considered within the scope of a feedback suppression as a kind of a preconditioned measure - additionally or alternatively to the aforesaid embodiments of the method. In the case of the alternative embodiment, the above described taking of an action if the measure overshoots the reference measure as well as the comparison of the measure and the reference measure necessary for determining any overshooting may be omitted. The aforesaid feedback suppression is especially implemented by a filter. Preferably, it is implemented by a controller that is adapted to determine if any and by which extend acoustic signals emitted by the receiver are detected by the microphone that is comprised by the hearing device. Such a "feedback" usually causes an awkward and undesired whistling sound during acoustic sound output. Therefore, the respective controller is furthermore adapted to suppress feedback sound signals as thoroughly as possible from an overall signal detected by the microphone. As already described above, the (vibration) measure contains information about the frequency response of the receiver and, thus, about the sound signal output by the receiver. Therefore, it is possible to save computing time in the controller for feedback suppression. Especially, by means of the vibration sensitive sensor the aforesaid controller receives information about the topical sound output of the receiver faster in respect to the runtime of the acoustic signal (for example about 30 microseconds earlier than the acoustic reception by the microphone). Thus, feedback suppression can be accelerated. The hearing device is, in that case, especially a hearing assistance device.

Expediently, the measure can also be used for a checkup of the proper function of the feedback suppression itself. For this purpose, the measure or a further comparison measure derived from the measure is compared with the part of the sound detected by the microphone which has been identified as a feedback signal.

According to a further embodiment of the method that optionally constitutes also an invention for itself and wherein the hearing device resembles especially a hearing assistance device with a microphone, by means of a comparison of the measure and a signal output by the microphone a defect of the microphone is detected. As an action, in that case, information about the defect of the microphone is output. Preferably, an especially predefined test signal is being output by means of the receiver. Beneficently, especially by means of the aforesaid controller for feedback suppression it is subsequently determined whether the signal output by the microphone is formed by parts from the signal output by the receiver and fed back by way of airborne sound or structure borne sound to the microphone.

Therefore, in the scope of that embodiment a comparison of the measure with the reference measure can be omitted. Preferably, the aforesaid checkup of the microphone regarding its proper function is employed in combination with one of the aforesaid embodiments of the method, yet.

According to an expedient embodiment of the method, information about a distortion, especially a so called harmonic distortion ("total harmonic distortion") and/or a so called intermodulation distortion of the acoustic emission of the receiver is derived from the vibration measure - additionally or alternatively to the frequency response of the receiver. Recognizably, a distortion is influenced at a half or a third of the peak frequency by the amplitude (also: "level" of the peak) since the peak enhances the harmonic frequencies. Furthermore, the height of the peak varies immediately even by the slightest clogging of the sound output opening. Also, a variation of the peak frequency can be detected easily. In addition to clog- ging of the sound output opening, a defect of the receiver (for example of its motor and/or its membrane) is reflected by enhanced distortion. In the scope of that embodiment, it is inferred from the information about the distortion to a defect of the receiver - additionally or alternatively to the detection of a clogging of the sound output opening. In that case, as an action (additionally or alternatively) information about the defect of the receiver and/or an instruction to change the receiver is issued, preferably.

According to a further expedient embodiment of the method, which constitutes also an invention for itself, the vibration measure is compared with a reference measure that is indicative for a fit of the earpiece supporting the receiver in the ear canal of the user. That embodiment of the method can be performed as an alternative or optionally as addition to the above described monitoring of the sound output opening in respect to clogging especially with cerumen. Especially, the reference measure of the embodiment is the same measure as for monitoring of the sound output opening in respect to clogging. Preferably, within the scope of the present embodiment the comparison in respect to the proper fit of the earpiece is conducted in a frequency range that differs from the frequency range used for monitoring the sound output opening in respect to clogging. If the measure overshoots the "fit reference measure" expediently an instruction to correct the fit of the earpiece inside the ear canal is issued as an action. Moreover, according to the present embodiment, the reference measure is expediently determined (i.e. calibrated) during an adaption of the hearing device. That means that the reference measure regarding the fit of the earpiece is calibrated when the receiver or the earpiece respectively are worn as intended in the ear, precisely inside the ear canal. Such an adaption is preferably conducted by trained personal, especially by an acoustician for hearing assistance devices. The present embodiment enables to continuously or intervallic check the fit of especially the receiver worn by means of the earpiece inside the ear canal, easily. That is beneficent especially with infants who are not able to realize a bad fit of the hearing device on the basis of an acoustic performance that is reduced in respect to the performance during adaption. According to an additional embodiment of the method that constitutes also an invention for itself, information about the type of the applied receiver is determined by way of comparing the (vibration) measure with the reference measure. As it is known, each type of receiver features an individual sound spectrum and, accordingly, also a distinctly assigned frequency response. Therefore, especially in the scope of hearing devices that are enabled for a change of the receiver it is possible to identify the type of the respective receiver, for example the size of the receiver (i.e. in the respective maximum output signal strength) by means of the electro-acoustic characteristics of the receiver itself. For example methods of pattern recognition are conducted to identify the type of the receiver. Preferably, as an action subsequently settings of a signal processing module are adapted to the newly identified receiver. The signal processing module is preferably constituted by a signal processor designed to adapt audio input signals according to preferably user specific sound characteristics and to afterwards transmit them to the receiver. Within the scope of this embodiment it is also possible that the aforementioned monitoring of the sound output opening with respect to clogging, the monitoring of the receiver regarding a defect, the monitoring the correct fit of the earpiece along with the respectively assigned features, especially the comparison of the measure with the reference measure regarding a possible overshooting, are dispensed with. However, the present embodiment is preferably combined with one of the embodiments described above.

The hearing device according to the invention comprises the aforementioned signal output transducer as well as the vibration sensitive sensor assigned to that transducer. The vibration sensitive sensor is coupled indirectly or directly to the transducer (as described above). Furthermore, the hearing device comprises the above mentioned signal processing module, i.e. the signal processor. The signal processing module is adapted to conduct the method as described above, especially according to one or the combination of several of the above described embodiments of the method.

For example, the hearing device is constituted generally by the receiver that preferably is to be worn at the ear or in the ear canal. As further examples, the hearing device is constituted by headphones, especially in-ear-headphones, by so called "hearables", by headsets, by communication devices, by hearing assistance devices (also: hearing aids) or the like. Especially the hearing assistance device is in particular constituted by a behind the ear or in the ear hearing aid.

According to a preferred embodiment of the hearing device, the signal processing module, i.e. the signal processor, is built at least fundamentally by a microcontroller with a processor and a data storage. In the data storage, the functionality to conduct the method according to the invention is implemented by means of an operating software ("firmware") as a program such that the method can be conducted - optionally by interaction with the user of the hearing device - automatically by executing the operating software in the microcontroller. Within the scope of the invention, the signal processing module is alternatively constituted by a nonprogrammable electronic component, such as an ASIC, inside of which the functionality for conducting the method according to the invention is implemented by means of circuitry.

According to preferred embodiment of the hearing device, the vibration sensitive sensor is positioned on the outside of a receiver housing, in particular of its housing wall. According to an alternative embodiment, the sensor is in contrast positioned on the inside of the housing wall, i.e. in the inside of the receiver housing. In both cases the sensor is preferably connected permanently to the receiver. Especially the sensor is build integral with the receiver.

The receiver is preferably designed as a so called "balanced armature receiver". According to an optional embodiment, the receiver is built as a dynamic transducer, a condenser receiver, a piezo receiver, a micro-electro-mechanical-system (MEMS) or the like. By means of the calibration of the reference measure and/or by means of predefining the limit value as described above, especially different characteristics of these receivers, for example different reactions to clogging of the sound output opening are considered. According to an alternative embodiment, the vibration sensitive sensor is positioned at the earpiece supporting the receiver with a distance to the housing wall of the receiver being especially small in regard to the size of the whole hearing device. In that case, the receiver is manufactured separately from the sensor and preferably also changeable separately.

According to a further expedient embodiment of the hearing device, the receiver is designed as a so called double receiver. In that case, the receiver comprises two membranes for generating (airborne) sound that vibrate mirror inverted (i.e. symmetrically opposed) during intended operation. Preferably, one common sound output opening is assigned to both membranes. In particular a common receiver sprout is assigned to both membranes. Since the vibrations of both membranes especially in direction normal to the plane of the membranes compensate each other during intended operation the vibration sensitive sensor is arranged with its sensor direction along the direction of the planes of the membranes with regard to the receiver. Then, the vibrations directed in the direction of the planes of the membranes do not compensate each other. Here and in the following, the term "sensor direction" is to be understood especially that it forms the direction along which the sensor is able to detect vibration.

According to another expedient embodiment of the hearing device, the receiver is also designed as a double receiver with the membranes vibrating mirror inverted during intended operation. However, in that embodiment a respective sound output opening is assigned to each of the membranes. Preferably, one respective receiver spout as well as one respective sound canal with a respective sound output opening in the earpiece are assigned to each of the membranes. Especially, a respective cerumen guard is assigned to each of the sound output openings, as well. The cerumen guard can be one single part that serves for protection of both sound output openings. Otherwise, there can be one cerumen guard for each sound output opening. According to that embodiment, the sensor is preferably aligned with its sensor direction along the direction normal to both membranes. Hereby, by means of the sensor a vibration is especially not detected until one of both sound output openings are clogged at least partly. Due to such asymmetric clogging of both sound output openings the two receiver parts get distorted against each other in respect to the vibration, i.e. they vibrate unsymmetrically. The present embodiment enables an especially sensitive detection of a clogging of the sound output openings with cerumen, since it is supposed that both sound output openings will be clocked differently with cerumen, with a high probability.

The vibration sensitive sensor is preferably resembled by a MEMS. Alternatively, the sensor is resembled by a conventional electret microphone whose sound input opening is closed against intrusion of cerumen and air such that it is only sensitive for structure born sound, i.e. for vibration. Additionally, that electret microphone is preferably adapted with its sensitivity to the present frequency of the receiver.

According to a further expedient embodiment, the vibration sensitive sensor is connected to the feedback filter described above, i.e. to the controller for feedback suppression. Such feedback filter is normally provided by especially a hearing assistance device in any way. Therefore, input ports expediently provided for wiring, in any way, are used for the vibration sensitive sensor whereby it is enabled to safe wiring effort.

In the following, embodiments of the invention are described by means of a drawing. The respective figures show:

Fig. 1 : a hearing device by means of a schematic interconnection illustration,

Fig. 2: a vibration spectrum of a receiver of the hearing device in a schematic diagram,

Fig. 3: a sequence of a method for monitoring electro-acoustic- performance of the hearing device according to figure 1 in a schematic operational diagram, in principle, and

Fig. 4 to 8: in a schematic side view several respectively alternative embodiments of a receiver of the hearing device with a vibration sensitive sensor. Equivalent parts and dimensions are provided with the same reference signs in all figures.

Figure 1 shows a hearing device 1 in form of a hearing assistance device. The hearing device 1 comprises a housing 2 that encases a number of electric components of the hearing device 1 . As such electric components encased by the housing 2 the hearing device 1 comprises two microphones 3 for detection of sounds as well as a signal processor 4. By that signal processor 4 during intended operation of the hearing device 1 the detected sounds, in particular audio input signals output by the microphones 3 and constituting the sounds in the way of electric signals, are filtered by means of deposited signal processing algorithms, amplified and provided as audio output signals for transformation into an acoustic signal (i.e. airborne sound). For transformation of the audio output signals the hearing device 1 comprises a signal transducer, in particular a receiver 5 that is aligned outside of the housing 2 and connected by means of a cable link 6 mechanically to the housing 2 and electrically (in terms of signal transmission) to the signal processor 4. Additionally, the receiver 5 is surrounded by an earpiece 7. In the present embodiment according to Fig. 1 the earpiece 7 is constituted by a so called ear dome that is not adapted specifically to an ear canal of an individual user of the hearing device 1 . Rather, the earpiece 7 is made of flexible material and devised as a standard element made for usage by a plurality of users. In particular, the hearing device 1 is constituted by a so called receiver-in-canal-hearing aid that is also named as RIC-hearing aid or shortly RIC.

The hearing device 1 comprises additionally a vibration sensitive sensor which is named in the following as vibration sensor 8. That vibration sensor 8 is assigned to the receiver 5 and, thus, positioned in the earpiece 7, as well. According to an alternative embodiment that is not displayed here, the vibration sensitive sensor is positioned on the outside of the earpiece 7.

The vibration sensor 8 serves for detection of vibrations that are caused by the sound production of the receiver 5 during intended operation of the hearing device 1 . For processing of the measurement signals - i.e. for evaluation of these meas- urement signals - the vibration sensor 8 is connected to the signal processor 4. The signal processor 4 is adapted to determine as a measure a frequency response of the receiver from the measurement signals. Thereby, the measure is characteristic for the vibration of the receiver 5. Therefore, the vibration sensor 8 can provide information about electro-acoustic performance of the receiver 5 and, thus, of the whole hearing device 1 .

In an intended wearing position the receiver 5 is aligned with the earpiece 7 inside the ear canal of the individual user. Therefore, the receiver 5 is prone to the cerumen produced in the ear canal which can cause obstruction, in particular clogging of a sound output opening 9 of the earpiece 7. In order to prevent that cerumen can get through the sound output opening 9 to the receiver 5 the earpiece 7 comprises a cerumen guard (also: wax filter) which is not displayed here in detail. In the scope of the displayed ear dome the cerumen guard is resembled by a cover of the sound output opening 9 in form of some kind of cover or sieve that exhibits a plurality of smaller passage openings that enable prevention or at least reduction of an intrusion of cerumen. However, these passage openings are also prone to clogging or covering with cerumen from an outside. In case of clogging as well as a just partly clogging of the sound output opening 9 the eardrum of the user would only receive parts of the sound output by the receiver 5.

The signal processor 4 is designed for executing a method described in detail in the following. As it is shown in Fig. 2 the measure detected by means of the vibration sensor 8 varies with increased clogging of the sound output opening 9. Fig. 2 displays a vibration spectrum of the receiver 5 determined by means of the vibration sensor 8. In Fig. 2 there is particularly shown a dimension I derived from an amplitude of the detected vibration (or the amplitude itself) marked in decibel over a (logarithmically marked) frequency f. The dotted line shows the vibration spectrum of the receiver 5 in case of an open, i.e. completely unobstructed sound output opening 9. The broken line shows the vibration spectrum in case of a partly obstructed sound output opening 9 and the continuous line shows the vibration spectrum in case of a completely blocked sound output opening 9. The method executed by the signal processor 4 serves for monitoring electro- acoustic performance of the receiver 5. Therefore, the signal processor 4 determines in a calibration step 20 at first a reference measure for the measure, in particular a reference distribution of the frequency response of the receiver 5. The reference distribution thus shows the frequency response for known environment conditions, in particular in case of an open sound output opening 9. The reference measure is stored for later availability in a search module of the signal processor 4.

In as subsequent method step 30 the signal processor determines by means of the vibration sensor 8 - caused by an input of the user, after a predefined interval or due to reaching a predefined state of the hearing device 1 - the measure for the vibration of the receiver 5. For that purpose, for example an acoustic test signal is output by means of the receiver 5 or the sound output of the receiver 5 during normal operation is used.

Subsequently, within a comparison step 40 the measure is compared with the reference measure and it is determined whether the measure overshoots the reference measure by 2 decibel or more. In that case, within an instruction step 50 as an action an instruction is issued to change the earpiece 7. Subsequently to the change of the earpiece the method step 30 is repeated.

If the measure does not overshoot the reference measure the monitoring of the electro-acoustic performance is terminated in a method step 60 (for example until the next triggering).

In the case that for determining the measure the receiver 5 is metered during normal operation by means of the vibration sensor 8, the method for monitoring as described above is running in the background.

According to another embodiment of the invention, the change of the earpiece 7 is realized on the basis of the measure determined by means of the vibration sensor 8. Hereby, a characteristic snapping sound, i.e. a peak at distinct frequencies, is detected within the vibration spectrum. Alternatively, the user has to confirm the change of the earpiece 7 by means of a respective input, for example by operating a remote control, by operating a switch or the like.

Fig. 4 shows an embodiment of the receiver 5 and of the vibration sensor 8. The receiver 5 exhibits an outer shape being approximately box shaped. The shape being composed by a receiver housing 70 and having rounded corners and edges. Inside of this receiver housing 70 there is a membrane stretched along a length direction 72 of the receiver 5 (not shown in detail). During intended operation of the receiver 5 the membrane is vibrated by a drive section also named as "motor". At a face side 74 of the receiver housing 70 there is a sound socket 76 (also named as "receiver sprout"). That sound socket 76 is founded about a sound opening in the receiver housing 70. Through that sound socket 76, the airborne sound caused by the vibrating membrane exits from the receiver housing 70. By means of that sound socket 76, the receiver 5 is inserted into a sound canal 78 adjoining the sound output opening 9 on the inside of the earpiece 7.

According to the embodiment of Fig. 4, the vibration sensor 8 is put directly onto the speaker housing 70. In particular, the vibration sensor 8 is connected fixedly, i.e. inseparable, with the receiver housing 70 and, thus, together with the receiver 5 constitutes one unit. At hand, the vibration sensor 8 is aligned with its sensor direction 80 perpendicular to the length direction 72 and, thus, also perpendicular to the plane of the membrane of the receiver 5. The term "sensor direction 80" is understood to be a direction along which the vibration sensor 8 is sensitive for vibration. In the present embodiment the vibration sensor 8 is furthermore positioned at a spot of the receiver housing 70 being remote from the sound socket 76.

Fig. 5 shows an alternative embodiment of the receiver 5, wherein the vibration sensor 8 is located as near as possible to the sound socket 76. In that case, variations of the vibration caused by clogging of the sound output opening 9 (or possibly also of the sound socket 76) can be detected especially well. According to a further alternative embodiment shown in Fig. 6, the vibration sensor 8 is integrated into the receiver 5. That means that the vibration sensor 8 is located inside of the receiver housing 70. In that case, the vibration sensor 8 is aligned with its sensor direction 80 along the length direction 72.

Fig. 7 shows another alternative embodiment wherein the receiver 5 is designed as a so called double receiver. In that case, the receiver 5 comprises two fully- fledged receivers (each named as "subreceiver 82") that are fitted together in parallel to the length direction 72. In particular, both subreceivers 82 are enclosed by a common housing (also named as receiver housing 70). For illustration the common receiver housing 70 is illustrated in parts, however. The respective sound outputs of both subreceivers 82 open out into one common sound socket 76. That means that the double receiver according to Fig. 7 only has one sound socket 76. The subreceivers 82 are furthermore aligned such that during intended operation the respective membranes of both subreceivers 82 vibrate mirror-inverted. Therefore, in respect to the whole receiver 5 the vibrations being perpendicular to the plane of the membranes compensate each other. Because of that, the vibration sensor 8 according to the present embodiment is positioned with its sensor direction 80 along the length direction 72, i.e. perpendicular to the main direction of vibration of the membranes. That is because the vibrations of both membranes do not compensate each other in length direction 72.

Fig. 8 shows another alternative embodiment of the receiver 5, wherein the receiver 5 is also designed as a double receiver. However, according to the present embodiment one respective sound socket 76 is assigned to each of the

subreceivers 82. In case of clogging of the respective sound output opening 9 assigned to the respective sound socket 76 an unbalance of vibration is caused between both subreceivers 82 since with high probability both sound output openings 9 would not be clogged by the same degree. Such unbalance of vibration can be detected easily by means of the vibration sensor 8 being aligned with its sensor direction 8 along the main vibration direction of both membranes. Otherwise, without clogging the such aligned vibration sensor 8 will detect no or just insignificant vibrations during operation. According to an embodiment not illustrated in detail, the receiver 5 and the vibration sensor 8 resemble a common unit as described above. In that embodiment the signal ports of the vibration sensor 8 and of the receiver 5 are combined in a common port, especially in a common line, in particular in a common cable.

The common unit made up from the receiver 5 and the vibration sensor 8 constitutes an invention for itself, as well. The subject matter of the invention is not constricted by the embodiments described above. Rather, further embodiments of the invention can be derived from the specification above by a person skilled in the art. Especially, the respective features of the invention described by the different embodiments can be combined with each other in other ways, also.

List of reference signs

1 hearing device

2 housing

3 microphone

4 signal processor

5 receiver

6 cable link

7 ear piece

8 vibration sensor

9 sound output opening 20 calibration step

30 method step

40 comparison step

50 instruction step

60 method step

70 receiver housing

72 length direction

74 face side

76 sound socket

78 sound canal

80 sensor direction

82 subreceiver f frequency

I dimension