EP4187926A1

EP4187926A1 - Method and system for providing hearing assistance

Info

Publication number: EP4187926A1
Application number: EP21211356.7A
Authority: EP
Inventors: Daniel LUCAS-HIRTZ; Daniel Holenstein; Matthias Riepenhoff
Original assignee: Sonova AG
Current assignee: Sonova Holding AG
Priority date: 2021-11-30
Filing date: 2021-11-30
Publication date: 2023-05-31

Abstract

There is provided a method for providing hearing assistance to a user (16) wearing a hearing device (12R, 12L), comprising: capturing, by a microphone arrangement (40) of the hearing device (12R, 12L), a local sound comprising the user's own voice at a location of the user, to provide an own voice signal; transmitting the own voice signal from the hearing device to a remote microphone device (14) at a location remote from the user; capturing, by a microphone arrangement (28) of the remote microphone device (14), a remote sound at the location of the remote microphone device (14) to provide a remote audio signal; processing, by the remote microphone device, the remote audio signal so as to generate an output audio signal, taking into account the received own voice signal in a manner so as to reduce a signal contribution of the user's own voice in the output audio signal; transmitting the output audio signal from the remote microphone device to the hearing device; and stimulating, by the hearing device, the user's hearing based on the received output audio signal.

Description

The invention relates to a method and system for providing hearing assistance to a user wearing a hearing device and utilizing a remote microphone device wirelessly connected to the hearing device.
To use a hearing device, in particular a hearing aid, with an external wireless microphone may increase the signal-to-noise-ratio (SNR) by bringing the wireless microphone closer to the speaker than the built-in microphone of the hearing device. However, depending on the distance between the external microphone and the user of the hearing device, the external microphone also may pick up the user's voice when the user speaks; the respective audio signal containing own voice of the user then will be transmitted to the hearing device and a corresponding own voice signal will be reproduced via the output transducer of the hearing device and can be perceived by the user.
WO 2019/233588 A1 relates to a binaural hearing aid system which is used with a wireless table microphone which forms multiple beams. The hearing aid system may provide the table microphone with user's own voice information, so that the table microphone can determine into which of the multiple beams the user is presently speaking, thereby determining a direction of arrival of the user's voice on the table microphone. The audio signals captured by the table microphone may be processed based on an appropriate HRTF, so as to simulate the positioning of a listener at the position of the table microphone.
It is an object of the invention to provide for a hearing assistance system and method, wherein a table microphone device is used with a hearing device, wherein annoying own voice perception is reduced or eliminated. It is a further object to provide for a table microphone device for use with such hearing assistance method and system.
According to the invention, these objects are achieved by a method as defined in claim 1, and a table microphone device as defined in claim 6, respectively.
The invention is beneficial in that, by transmitting an own voice signal provided by the hearing device to the remote microphone device and processing the remote audio signal captured by the remote microphone device by taking into account the own voice signal received from the hearing device in a manner so as to reduce a signal contribution of the user's own voice in the output audio signal generated by the remote microphone device relative to a signal contribution of the user's own voice in the captured remote audio signal, annoying own voice perceptions resulting e.g. from latency of an own voice signal reproduced by the output transducer of the hearing device can be reduced or avoided.
According to one example, the remote microphone device may determine a delay of the received own voice signal relative to the signal contribution of the user's own voice in the remote audio signal, determine a level of the signal contribution of the user's own voice in the remote audio signal, and at least partially remove the signal contribution of the user's own voice from the remote audio signal by taking into account the determined delay of the received own voice signal and the determined level of the signal contribution of the user's own voice in the remote audio signal. In this way, a noise canceling procedure may be implemented, wherein the own voice content is considered as noise.
Such a noise canceling procedure is particularly efficient at low and medium frequencies, such as 50 Hz to 500 Hz.
According to another example, the remote microphone device determines a direction of arrival of the signal contribution of the user's own voice content in the remote audio signal and controls an adaptive beamformer implemented by the microphone arrangement of the remote microphone device for providing the output audio signal in such a manner that the beam of the adaptive beamformer points in a direction different from the determined direction of arrival of the user's own voice, so as to reduce the signal contribution of the user's own voice in the output audio signal.
The direction of arrival of the user's own voice may be determined by comparing the remote audio signal to the received own voice signal.
Such own voice reduction by beamforming is particularly efficient at higher frequencies. In particular, such beamforming procedure may be combined with the above-mentioned active noise canceling procedure so as to efficiently remove own voice content over the entire speech frequency range.
The beam of the adaptive beamformer pointing in the direction different from the determined direction of arrival of the user's own voice may be provided by a directivity of the beam and/or a pattern of the beam, e.g. a polar beam pattern, by which the remote sound captured by the remote microphone device from the direction of arrival of the user's own voice is effectively reduced and/or minimized in the output audio signal as compared to the remote sound captured by the remote microphone device from at least another direction different from the direction of arrival of the user's own voice, at least within a frequency range significant for the user's own voice. For instance, the beam may be provided with a beam pattern comprising a reduced sensitivity range and/or a minimum sensitivity angle. The reduced sensitivity range of the beam pattern may be defined as an angular range at which the remote sound captured by the remote microphone device is reduced in the output audio signal as compared to the remote sound captured within a remaining angular range of the beam pattern. The minimum sensitivity angle may be defined as an angle of the beam pattern at which the remote sound captured by the remote microphone device is minimally amplified and/or maximally reduced in the output audio signal as compared to the remote sound captured at other angles of the beam pattern. The beam of the adaptive beamformer pointing in the direction different from the determined direction of arrival of the user's own voice may then be provided by orienting the reduced sensitivity range and/or the minimum sensitivity angle of the beam pattern toward the determined direction of arrival of the user's own voice. E.g., the minimum sensitivity angle may be comprised in the reduced sensitivity range of the beam pattern. E.g., the beam pattern may have a cardioid shape.
The own voice signal may be provided as an audio signal comprising audio data indicative of the user's own voice, and may then be referred to as an own voice audio signal. An audio signal may be generally defined as a signal allowing to reproduce a sound based on audio data contained therein. The own voice signal may also be provided as a data signal comprising data different from audio data, e.g. a signature representative of the user's own voice, and may then be referred to as an own voice data signal. In particular, the signature can comprise any information about the user's own voice, e.g. an envelope of the level of the user's own voice and/or a signal pattern characteristic of the user's own voice such as, e.g., information about an occurrence of onsets and/or vowels and/or consonants and/or voiced phonemes and/or unvoiced phonemes in the user's own voice. The own voice signal can thus comprise information allowing to identify a signal contribution of the user's own voice in the remote audio signal.
For instance, the own voice signal may be provided as an audio signal indicative of the local sound captured by the microphone arrangement of the hearing device. E.g., the own voice signal may be an ambient sound captured at the location of the user which can contain the user's own voice when the user is speaking and may also contain other sound captured in the ambient environment of the user. Thereby, it can be assumed that the local sound captured by the microphone arrangement of the hearing device is more representative of the user's own voice than the remote sound captured by the microphone arrangement of the remote microphone device, e.g., due to a larger distance of the remote microphone device to the user as compared to the hearing device worn by the user.
As another example, the own voice signal may be provided as an audio signal by a processing of the audio signal indicative of the local sound captured by the microphone arrangement of the hearing device. The audio signal processing may be performed by a processor included in the hearing device and/or remote microphone device. For instance, the processor may be configured to extract and/or predominantly include sound information of the user's own voice contained in the audio signal indicative of the local sound captured by the microphone arrangement of the hearing device, e.g. by implementing a beamformer in the hearing device which may be directed toward the user's mouth. Thereby, a quality of the own voice signal may be improved by the audio signal processing. Such improvement can be employed to facilitate identifying a signal contribution of the user's own voice in the remote audio signal when taking into account the own voice signal.
As another example, the microphone arrangement of the hearing device may be implemented as an own voice detector configured to detect, based on the captured local sound, an activity of the user's own voice, and the own voice signal may be provided as an audio signal and/or a data signal indicative of the detected user's own voice activity.
As another example, the own voice signal may be provided as a data signal by a processing of the local sound captured by the microphone arrangement of the hearing device to extract a signature representative of the user's own voice, e.g. by a processor included in the hearing device and/or remote microphone. In some implementations, when capturing the remote sound, the microphone arrangement of the remote microphone device can be configured to operate in an omnidirectional mode and/or in a directional mode. In the omnidirectional mode, the remote sound may be amplified over a total angular detection range of the microphone arrangement. For instance, the omnidirectional mode may be employed to amplify ambient sound at the location of the remote microphone over the total angular detection range when no speaker is present in the ambient environment, e.g. when no speech is detected by the remote microphone in the remote sound. In the directional mode, the remote sound may be amplified at an increased level for at least one preferential direction within the angular detection range at which the captured sound is amplified at an increased level. For instance, the directional mode may be employed to amplify the speech of a speaker localized in the ambient environment, e.g. when a presence of speech in the remote sound is detected by the remote microphone. The remote microphone may be configured to switch between the omnidirectional mode and the directional mode, e.g. depending on whether the speech is detected by the remote microphone in the remote sound. In some implementations, when taking into account the received own voice signal in a manner so as to reduce a signal contribution of the user's own voice in the output audio signal, the adaptive beamformer implemented by the microphone arrangement of the remote microphone device can be employed in the omnidirectional mode and/or in the directional mode of the remote microphone device to point the beam of the adaptive beamformer in a direction different from the determined direction of arrival of the user's own voice. This may imply that a directivity of the beam and/or a pattern of the beam in the omnidirectional mode and/or in the directional mode is accordingly adjusted depending on the received own voice signal, in particular depending on the determined direction of arrival of the user's own voice.
In some implementations, the remote microphone device is a stationary microphone device, e.g. a table microphone. In some implementations, the remote microphone device is a microphone device configured to be worn by another person different from the user, e.g. a clip-on microphone or a hearing device.
Further preferred embodiments of the invention are defined in the dependent claims.
Hereinafter, examples of the invention will be illustrated by reference to the attached drawings, wherein:

Fig. 1: is a schematic illustration of a use situation of a binaural hearing device system and a table microphone device;
Fig. 2: is a block diagram of a hearing assistance system comprising a binaural hearing device system and a table microphone device;
Fig. 3: is a block diagram similar to Fig. 2, wherein a second example is shown; and
Fig. 4: is an example of a polar beam pattern which may be provided by an adaptive beamformer included in the table microphone device illustrated in Fig. 3.

A "hearing device" as used hereinafter is any ear level device suitable for reproducing sound by stimulating a user's hearing, such as an electroacoustic hearing aid, a bone conduction hearing aid, an active hearing protection device, a hearing prostheses device such as a cochlear implant, a wireless headset, an earbud, an earplug, an earphone, etc.
Fig. 1 illustrates a use situation of a binaural hearing device system 10 comprising a first hearing device 12R and a second hearing device 12L, which system is wirelessly connected to a remote microphone device 14 implemented as a table microphone device. The hearing devices 12R and 12L are worn at the right ear and at the left ear, respectively, of a user 16.
The table microphone device 14 is placed on a table 18 at which other persons, e.g. a person 20, are located. When the person 20 speaks, the table microphone device 14 captures audio signals from the person's voice 22 and transmits the audio signals, after some processing, via a wireless link 24 to the binaural hearing system 10 for reproduction by the output transducers of the hearing devices 12R and 12L. Since the table microphone 14 is much closer to the person 20 than the built-in microphones of the hearing devices 12R, 12L, the SNR can be improved.
However, when the user 16 speaks, the table microphone device 14 captures an audio signal which includes the user's voice 26. When such audio signal containing the user's voice is sent via the link 24 to the hearing system 10 and is reproduced by the hearing devices 12R, 12L with some latency, this may result in an annoying perception of the delayed own voice by the user 16.
For example, it has been found that the perception of the own voice by the user from the audio signal transmitted by the external microphone may be found as being annoying as soon as the latency reaches a certain threshold, which may be, for example, between 15 and 25 ms. For example, a latency of 40 ms usually will be already found to be quite annoying. In addition to the latency the level of the captured own voice signal is important for the perception of whether or not the own voice signal reproduced by the hearing device is felt to be annoying. For example, in a classroom or conference room, a typical distance between the user of the hearing device and the wireless microphone typically may be as large as around 10m, so that the own voice level and the respective disturbing effect may be low. In contrast, when using a wireless microphone in a private context, for example in a typical "restaurant" setup with a few people talking together on a table, the microphone distance is likely to be much lower, so that the relative level of the own voice microphone signal reproduced by the hearing device is likely to be much higher.
Fig. 2 is a schematic illustration of a system in which the content of own voice in the audio signal transmitted from the table microphone device 14 to the hearing device system 10 is reduced or eliminated.
The table microphone device 14 comprises a microphone arrangement 28 including a plurality of microphones 30 and a microphone signal processing unit 32, a main audio signal processing unit 34 and a transceiver unit 36. The microphone signal processing unit 32 may be suitable for implementing an adaptive beamformer.
The binaural hearing system 10, which is formed by the two hearing devices 12R, 12L, comprises a transceiver unit 38 for establishing a bidirectional wireless link 24 with the transceiver unit 36 of the table microphone device 14. The transceiver unit 38 of the hearing system 10 may be implemented in one of the two hearing devices 12R, 12L or in both of them; in the example of Fig. 2, only the hearing device 12R is shown with a transceiver unit 38. Each hearing device 12R, 12L comprises a microphone arrangement 40 and an output transducer 42.The sound captured by the microphone arrangement 40 at the location of the user is provided as an audio signal, which may be referred to as a local audio signal. The local audio signal can be modified by a processor (not shown) included in at least one of the hearing devices 12R, 12L.The processor may be configured, for instance, to provide for beamforming or other sound processing, which may include a detection of the user's own voice in the audio signal. The hearing devices 12R, 12L may be, for example, hearing aids or hearing prosthesis devices.
The transceiver units 36 and 38 act as a wireless interface for the hearing system 10 and the table microphone device 14, respectively, which allows to establish a wireless link 24 between the hearing system 10 and the table microphone device 14 for exchanging audio signals.
When the user 16 speaks, the user's own voice 26 is captured both by the microphone arrangement 30 of the table microphone device 14 and by the microphone arrangements 40 of the hearing devices 12R, 12L. The hearing devices 12R and 12L together may implement a binaural beamformer; this allows not only to improve the SNR of a target signal of the hearing device system 10 (such as speech of another person), but also allows to capture the own voice 26 of the user 16 in a particularly efficient manner. In this way, by capturing a local sound comprising the user's own voice at the location of the user, an own voice signal can be provided. The own voice signal may correspond to the audio signal generated by the microphone arrangement 40 based on the captured local sound and/or a modified audio signal provided by the processor of the hearing devices 12R, 12L, e.g. by the binaural beamforming which may be directed toward the user's mouth to improve the SNR, and/or any other data signal representative of the user's own voice which can be provided by the processor of the hearing devices 12R, 12L based on the audio signal generated by the microphone arrangement 40 from the captured local sound, e.g. a signature of the user's own voice.
The thus provided own voice signal is transmitted via the wireless link 24 from the hearing device 12R to the table microphone device 14, where it is supplied to an own voice identifying unit 44 of the audio signal processing unit 34. The microphone arrangement 28 of the table microphone 14 generates an audio signal based on a remote sound captured at the location of the table microphone device 14, e.g. an ambient sound, which, when the user 16 speaks, includes a content of own voice 26 of the user 16. The remote audio signal provided by the microphone arrangement 28 of the table microphone device 14 is supplied both to the own voice identifying unit 44 and a delay unit 46 of the main audio signal processing unit 34. The own voice identifying unit 44 determines the amplitude or level of a signal contribution of the user's own voice in the remote audio signal and the delay of the received own voice signal relative to the signal contribution of the user's own voice in the remote audio signal by comparing the remote audio signal, as obtained from the microphone arrangement 28, and the own voice signal received from the hearing device system 10 via the link 24. To this end, the own voice signal received from the hearing device system 10 via the link 24 can be regarded as being representative for the user's own voice due to a close proximity of the hearing device system 10 to the user's mouth as compared to the more distant location of the table microphone device 14 allowing to draw conclusions about the signal contribution of the user's own voice in the remote audio signal.
The determination of a time shift between the received own voice signal and the signal contribution of the user's own voice in the remote audio signal may be based on a cross-correlation between these two signals. The precision of the determination of such a time shift may then depend on a sampling rate, which is used to calculate the cross-correlation of these digital signals. The higher the sampling rate, the more accurate the time shift can be determined. If the sampling rate is for example 10,000 samples per second, the time shift can be determined with an accuracy of +/- 0.1ms. When the user is close to the table microphone, a latency of the transmitted own voice signal to the microphone is dominated by the latency which arises from a protocol which is used for wireless transmission. This latency is typically larger than the time required for the sound of the user's voice to travel to the table microphone and thus results in a delay. Under these circumstances, the transmitted own voice signal is delayed relative to the signal contribution of the user's own voice in the remote audio signal. If the user is far away from to the table microphone, the signal contribution of the user's own voice in the remote audio signal would be delayed in comparison to the own voice signal received from the hearing device system.
The own voice signal received from the hearing device system 10 is also supplied to an attenuation unit 48 for being attenuated according to the determined level of the signal contribution of the user's own voice in the remote audio signal, and the remote audio signal is supplied to the delay unit 46 where it is delayed according to the determined delay of the received own voice audio signal relative to the signal contribution of the user's own voice in the remote audio signal. The delay in the delay unit 46 and the attenuation in the attenuation unit 48 are selected such that subtraction of the attenuated received own voice signal from the delayed remote audio signal results in removal of the signal contribution of the user's own voice in the remote audio signal. To this end, the delayed remote audio signal and the attenuated received own voice signal are supplied to a subtractor unit 50 where the attenuated received own voice signal is subtracted from the delayed remote audio signal, so as to obtain a "clean" output audio signal.
The output audio signal then is transmitted by the transceiver unit 36 via the wireless link 24 to the hearing system 10, where it is received by the transceiver unit 38 and then is supplied to the output transducer 42 for stimulating the hearing of the user 16 according to the received clean output audio signal.
Thus, the main audio signal processing unit 34 can implement a noise cancelling functionality wherein the own voice content in the captured ambient audio signal is considered as noise. In order to efficiently remove this noise from the remote audio signal the delay of the transmitted own voice signal needs to be precisely determined as explained above. However, other factors like the occurrence of acoustic reflections or a movement of the user may reduce the efficiency of the noise cancelling, in particular at higher frequencies. It has been found that such noise canceling is particularly efficient at low and medium frequencies, such as from 50 Hz to 500 Hz.
An alternative or additional procedure for reducing a signal contribution of the user's own voice in the remote audio signal captured by a table microphone device 14 is schematically illustrated in Fig. 3, wherein the own voice signal received from the hearing system 10 via the link 24 is supplied to a direction of arrival (DOA) unit 60 in which the remote audio signal provided by the microphone arrangement 28 of the table microphone device 14 is compared to the own voice signal received from the hearing device system 10 via the wireless link 24, so as to determine the direction of arrival of the own voice in the remote audio signal provided by the microphone arrangement 28 of the table microphone device 14. The determined direction of arrival then is supplied to the microphone signal processing unit 32 of the microphone arrangement 28, so as to control the adaptive beamformer implemented in microphone arrangement 28 in such a manner that the beam of the adaptive beamformer points away from the determined direction of arrival of the signal contribution of the user's own voice in the remote audio signal provided by the microphone arrangement 28. The spatially filtered audio signal, as provided by the adaptive beamformer of the microphone signal processing unit 32 based on the remote audio signal, can be input to a main signal processing unit 54 for further signal processing. A resulting output audio signal can then be provided to the transceiver unit 36 for being transmitted to the hearing device system 10.
By applying such adaptive beamforming controlled according to the DOA of the user's own voice, the signal contribution of the user's own voice in the remote audio signal can be reduced or eliminated, so that also the signal contribution of the user's own voice in the output audio signal transmitted by the transceiver unit 36 via the link 24 from the table microphone device 14 to the hearing system 10 is reduced or eliminated.
Such reduction or elimination of own voice content in the remote audio signal provided by the table microphone device 14 by appropriate control of the adaptive beamformer implemented by the microphone arrangement 28 is particularly efficient at higher frequencies, such as above 500 Hz, so that a particularly efficient reduction or elimination of the signal contribution of the user's own voice in the output audio signal of the table microphone 14 may be achieved by combining the noise reduction approach, as illustrated in Fig. 2, and the adaptive beam former control approach, as illustrated in Fig. 3. For example, in such combined embodiment, based on the example of Fig. 3, the main audio signal processing unit 54 in Fig. 3 could be implemented as the noise canceller implemented by the main audio signal processing unit 34 of Fig. 2.
Fig. 4 illustrates, in a logarithmic scale 78, a polar plot of a beam pattern 71 which may be provided by the adaptive beamformer included in the table microphone device 14 illustrated in Fig. 3. The beam pattern 71 comprises a first angular range 74 in which, at least over a certain frequency range, the beamformer implemented by the microphone arrangement 28 has a reduced detection sensitivity at which the sound captured by the microphone arrangement 28 is reduced in the output audio signal as compared to the sound captured by the microphone arrangement 28 in a second angular range 73 at which the beamformer implemented by the microphone arrangement 28 has an increased detection sensitivity. In the example, the first angular range 74 and the second angular range 73 each extend over an angular section of 180°. A reduced sensitivity range of the beamformer may be defined as the first angular range 74, and an increased sensitivity range of the beamformer may be defined as the second angular range 73. The controlling the adaptive beamformer provided by microphone arrangement 28 in such a manner that the beam of the adaptive beamformer points away from the determined direction of arrival of the own voice content may then be performed by controlling the adaptive beamformer to orient the reduced sensitivity range 74 of the beam pattern toward the determined direction of arrival of the user's own voice and/or the increased sensitivity range 73 of the beam pattern away from the determined direction of arrival of the user's own voice.
In the example illustrated in Fig. 4, the beam pattern 71 comprises a discrete angle 75 at which the beamformer implemented by the microphone arrangement 28 has the smallest detection sensitivity such that the sound captured by the microphone arrangement 28 is minimally amplified and/or maximally reduced in the output audio signal, at least over a certain frequency range. The discrete angle 75 may be referred to as a minimum sensitivity angle. The minimum sensitivity angle 75 is centered within the reduced sensitivity range 74 of the beamformer. The beam pattern comprises another angle 76, which may be referred to as a maximum sensitivity angle, at which the beamformer implemented by the microphone arrangement 28 has the largest detection sensitivity such that the sound captured by the microphone arrangement 28 is maximally amplified in the output audio signal, at least over said frequency range. The maximum sensitivity angle 76 is centered within the increased sensitivity range 73. The controlling the adaptive beamformer may thus be performed by controlling the adaptive beamformer to orient the minimum sensitivity angle 75 of the beam pattern toward the determined direction of arrival of the user's own voice and/or the maximum sensitivity angle 76 of the beam pattern away from the determined direction of arrival of the user's own voice. Thus, a reduction and/or removal of the signal contribution of the user's own voice in the output audio signal may be further enhanced. In the example illustrated in Fig. 4, the beam pattern 71 has a cardioid shape, which may also be referred to as a cardioid beam pattern. Rather pronounced edges of this beam pattern 71 at the minimum sensitivity angle 75 and/or a rather steep decline toward the minimum sensitivity angle 75 can further increase the effectiveness of the reduction and/or removal of the signal contribution of the user's own voice in the output audio signal. In the polar plot of this beam pattern 71, the minimum sensitivity angle 75 is diametrically opposed to the maximum sensitivity angle 76.

Claims

A method for providing hearing assistance to a user (16) wearing a hearing device (12R, 12L), comprising
capturing, by a microphone arrangement (40) of the hearing device (12R, 12L), a local sound comprising the user's own voice at a location of the user, to provide an own voice signal;

transmitting the own voice signal from the hearing device to a remote microphone device (14) at a location remote from the user;

capturing, by a microphone arrangement (28) of the remote microphone device (14), a remote sound at the location of the remote microphone device (14) to provide a remote audio signal;

processing, by the remote microphone device, the remote audio signal so as to generate an output audio signal, taking into account the received own voice signal in a manner so as to reduce a signal contribution of the user's own voice in the output audio signal;

transmitting the output audio signal from the remote microphone device to the hearing device; and

stimulating, by the hearing device, the user's hearing based on the received output audio signal.
The method of claim 1, further comprising:
determining, by the remote microphone device, a delay of the received own voice signal relative to the signal contribution of the user's own voice in the remote audio signal;

determining, by the remote microphone device, a level of the signal contribution of the user's own voice in the remote audio signal; and

at least partially removing the signal contribution of the user's own voice from the remote audio signal by taking into account the determined delay of the received own voice signal and the determined level of the signal contribution of the user's own voice in the remote audio signal.
The method of claim 2, wherein an amplitude of the received own voice signal is adjusted according to the determined level of the signal contribution of the user's own voice in the remote audio signal so as to generate a modified own voice signal, wherein the remote audio signal is delayed according to the determined delay of the received own voice signal so as to generate a delayed remote audio signal, and wherein the modified own voice signal is subtracted from the delayed remote audio signal, so as to at least partially remove the signal contribution of the user's own voice from the remote audio signal.
The method of one of the preceding claims, further comprising:
determining, by the remote microphone device, a direction of arrival of the user's own voice based on the signal contribution of the user's own voice in the remote audio signal;

controlling an adaptive beamformer implemented by the microphone arrangement (28, 32) of the remote microphone device (14) for providing the output audio signal in such a manner that the beam of the adaptive beamformer points in a direction different from the determined direction of arrival of the user's own voice, so as to reduce the signal contribution of the user's own voice in the output audio signal.
The method of claim 4, wherein the direction of arrival of the user's own voice is determined by comparing the remote audio signal to the received own voice signal.
A remote microphone device comprising:
a wireless interface (36) for receiving an own voice signal provided by a hearing device (12R, 12L) based on capturing a local sound at a location of a user (16) wearing the hearing device, the local sound comprising the user's own voice;

a microphone arrangement (28) for capturing a remote sound at a location of the remote microphone device remote from the user, to provide a remote audio signal;

an audio signal processing unit (32, 34) for processing the remote audio signal so as to generate an output audio signal, taking into account the received own voice signal in a manner so as to reduce a signal contribution of the user's own voice in the output audio signal;

wherein the wireless interface (36) is configured to transmit the output audio signal to the hearing device (12R, 12L).
The remote microphone device of claim 6, wherein the audio signal processing unit (34) is configured to determine a delay of the received own voice signal relative to the signal contribution of the user's own voice in the remote audio signal; to determine a level of the signal contribution of the user's own voice in the remote audio signal; and to at least partially remove the signal contribution of the user's own voice from the remote audio signal by taking into account the determined delay of the received own voice signal and the determined level of the signal contribution of the user's own voice in the remote audio signal.
The remote microphone device of claim 7, wherein the audio signal processing unit (32, 34) comprises
an attenuation unit (48) for adjusting the amplitude of the received own voice signal according to the determined level of the signal contribution of the user's own voice in the remote audio signal so as to generate a modified own voice signal,

a delay unit (46) for delaying the remote audio signal according to the determined delay of the received own voice signal so as to generate a delayed remote audio signal, and

a subtractor unit (50) for subtracting the modified own voice signal from the delayed remote audio signal, so as to remove own voice from the remote audio signal.
The remote microphone device of one of claims 6 to 8, wherein the audio signal processing unit (32, 34) comprises
an adaptive beamformer (32); and

a direction of arrival detection unit (60) configured to determine a direction of arrival of the user's own voice based on the signal contribution of the user's own voice in the remote audio signal, and to control the adaptive beamformer (32) in such a manner that the beam of the adaptive beamformer points in a direction different from the determined direction of arrival of the own voice, so as to reduce the signal contribution of the user's own voice in the output audio signal.
The remote microphone device of claim 9, wherein the direction of arrival detection unit (60) is configured to determine the direction of arrival of the user's own voice by comparing the remote audio signal to the received own voice signal.
The remote microphone device of one of claims 9 and 10, wherein the microphone arrangement (28) comprises a plurality of spaced apart microphones (30).
A system for providing hearing assistance to a user, comprising the remote microphone device (14) of one of claims 6 to 11 and a hearing device (12,R, 12L) configured to be worn by a user (12), the hearing device comprising:
a microphone arrangement (40) for capturing a local sound comprising the user's own voice at a location of the user, to provide an own voice signal;

a wireless interface (38) for transmitting the own voice signal to the remote microphone device and for receiving the output audio signal from the remote microphone device; and

an output transducer (42) for stimulation the hearing of the user based on the output audio signal received from the remote microphone device.
The system of claim 12, wherein the microphone arrangement (40) comprises an own voice detector configured to detect, based on the captured local sound, an activity of the user's own voice and to provide the own voice signal indicative of the detected own voice activity.
The system of claim 12 or 13, wherein the hearing device (12R, 12L) further comprises a processor for processing the captured local sound so as to generate the own voice signal.
The system of one of claims 12 to 14, wherein the hearing device (12R, 12L) is part of a binaural hearing device system (10).
The system of claims 14 and 15, wherein the processor comprised in the hearing device (12R, 12L) is configured to implement a binaural beamformer for generating the own voice signal.