EP4770134A1

EP4770134A1 - Hearing aid system with wireless synchronization and context-aware processing

Info

Publication number: EP4770134A1
Application number: EP25177946.8A
Authority: EP
Inventors: Nicolai Westergren; Tanveer BHUIYAN; Morten WESTERGAARD; Juan Manuel VÖLKER; Lena Nilsson; Michael Noes Gätke
Original assignee: Oticon AS
Current assignee: Oticon AS
Priority date: 2025-05-21
Filing date: 2025-05-21
Publication date: 2026-07-01

Abstract

In an aspect of the present disclosure, a hearing aid system comprises a first hearing aid and a second hearing aid, both configured for wireless communication. The first hearing aid comprises a first input unit providing a first electrical audio input signal, and a first noise reduction system comprising a first noise reduction parameter to attenuate noise and providing a first processed signal, and a first motion sensor for providing a first motion bias, and a first conversation detector for providing a first conversation parameter indicative of conversation likelihood, and a first output unit for providing a first audible output signal based on the first processed signal. The second hearing aid comprises a second input unit providing a second electrical audio input signal, and a second noise reduction system with a second noise reduction parameter to attenuate noise and providing a second processed signal, and a second conversation detector for providing a second conversation parameter indicative of conversation likelihood, and a second output unit for providing a second audible output signal based on the second processed signal. The first noise reduction parameter is determined based on the first motion bias and the first and/or second conversation parameters. The second noise reduction parameter is determined based on the first motion bias and/or the second conversation parameter.

Description

TECHNICAL FIELD

The present application relates to the field of noise reduction in hearing aid systems. Specifically, the present application generally relates to the synchronization of noise reduction parameters between a first hearing aid and a second hearing aid when the hearing aids are configured to exchange parameters for noise reduction. The present disclosure relates to the use of motion sensors in hearing aids. The application relates to the field of hearing aid signal processing. The application further relates to conversation detection and voice activity detection.

BACKGROUND

A hearing aid may comprise a motion sensor to obtain sensor values related to the movement, acceleration, and/or orientation of the hearing aid, when the hearing aid is mounted on a hearing aid user. The sensor values may be used for adjusting a noise reduction system constituted by a hearing aid. For example, certain patterns of movements detected in the sensor values may be indicative of certain listening intentions of the hearing aid user. The hearing aid may be configured to detect these patterns and then adjust the noise reduction system accordingly, so that it matches the hearing aid user's intention.
A hearing aid system comprises two hearing aids each comprising a motion sensor. The motion sensors in both of the hearing aids may not be aligned on the ears of the hearing aid user. This may result in different sensor values and may therefore affect how the noise reduction system behaves, and hence the hearing aid user may experience different sound scenes in the left and right ear unintentionally. This may result in a poorer listening experience.
Another issue may be a mismatch of voice activity detection or conversation detection between two hearing aids. For example, one of the two hearing aids may be positioned on the shadow side of the head relative to a conversational partner, and thereby receive a weaker or poorer speech signal compared to the hearing aid that is positioned on the sunny side, e.g., direct line-of-sight to the conversational partner. Thus, the hearing aid positioned on the sunny side is therefore more likely to be able to detect the presence of the conversational partner's voice or the presence of an ongoing conversation between the hearing aid user and the conversational partner compared to the hearing aid positioned on the shadow side. It is therefore more desirable to adjust the noise reduction system of each hearing aid according to the voice activity detection or conversation detection from the hearing aid placed on the sunny side.

SUMMARY

A hearing aid system:

In an aspect of the present disclosure, a hearing aid system comprises a first hearing aid. The hearing aid system comprises a second hearing aid. The first and second hearing aids are configured to wirelessly communicate with one another. The first hearing aid comprises a first input unit. The input unit is configured to provide a first electrical audio input signal. The first hearing aid comprises a first noise reduction system. The first noise reduction system comprises a first noise reduction parameter. The first noise reduction parameter is configured to attenuate noise in the first electrical audio input signal. The first noise reduction parameter is configured for providing a first processed signal based on the first electrical audio input signal. The first hearing aid comprises a first motion sensor. The first motion sensor is configured to provide a first motion bias of the first hearing aid. The first hearing aid comprises a first conversation detector. The first conversation detector is configured to provide a first conversation parameter. The first conversation parameter is indicative of the likelihood of a conversation in the first electrical audio input signal based on the first electrical audio input signal. The first hearing aid comprises a first output unit. The first output unit is configured to provide a first audible output signal based on the first processed signal.
Thereby, one advantage of the present disclosure is the ability of the second hearing aid to utilize the first motion sensor data, enabling synchronized and coordinated noise reduction behavior across both hearing aids. For example, when a stable wireless connection is present, the second hearing aid can base its noise reduction decisions on the first motion bias, ensuring consistent interpretation of user movement. This synchronization improves spatial awareness and listening comfort, especially in dynamic environments where head movements may indicate shifts in attention or conversational focus.
The second hearing aid comprises a second input unit. The second input unit is configured to provide a second electrical audio input signal. The second hearing aid comprises a second noise reduction system. The second noise reduction system comprises a second noise reduction parameter configured to attenuate noise in the second electrical audio input signal and for providing a second processed signal based on the second electrical audio input signal. The second hearing aid comprises a second conversation detector. The second conversation detector is configured to provide a second conversation parameter. The second conversation parameter is indicative of the likelihood of a conversation in the second electrical audio input signal based on the second electrical audio input signal. The second hearing aid comprises a second output unit. The second output unit is configured to provide a second audible output signal based on the second processed signal.
The first noise reduction parameter is determined based on the first motion bias. The first noise reduction parameter is determined based on the first conversation parameter and/or the second conversation parameter. The second noise reduction parameter is determined based on the first motion bias. The second noise reduction parameter is determined based on the first motion bias and/or the second conversation parameter.
The first and second input units may be configured to pick up sounds. The first input unit and second input unit may be configured to provide the first and second electrical audio input signals representing the picked-up sounds. The first and second input units may each comprise a microphone configured to pick up sound. The first and second electrical audio input signals may be based on the picked-up sounds by the microphones. The first and second input units may each comprise a plurality of microphones each configured to pick up sound. The picked-up sounds may comprise a speech sound generated by a human speaker. The speech sounds may be a desired sound for a user of the hearing aid. The picked-up sounds may comprise a noise sound generated by a noise source or a superposition of several noise sources. The noise sound may be an undesired sound for a user of the hearing aid.
The first noise reduction system may comprise a first beamformer. The first beamformer may be configured to provide a first directional signal based on the plurality of first electrical audio input signals by combining the first electrical audio input signals. The first beamformer may be a delay-and-sum beamformer, or a delay-and-subtract beamformer, a minimum variance distortionless response (MVDR) beamformer, or any other beamformer. The first noise reduction system may comprise a first post-filter. The first post-filter may be configured to provide a first post-filtered signal based on the first directional signal. The first post-filter may comprise one or more first filter coefficients. The first post-filter may be configured to filter the first directional signal based on the one or more first filter coefficients. The first filter coefficients may be determined based on, for example, the Wiener filter, or the log-spectral amplitude estimator, etc. The first processed signal may be based on the first post-filtered signal.
The first noise reduction system may constitute a digital signal processor that may be a computer processor of the first hearing aid. The first noise reduction system may be a signal processing system that is part of the digital signal processor. The first signal processing system may be configured to carry out numerical computations.
The first beamformer may be implemented in the frequency domain. The first beamformer may comprise a beamforming filter for each of the plurality of first electrical audio input signals. Each beamforming filter may comprise a plurality of beamforming filter weights. Thus, each beamforming filter coefficient may correspond to a complex value applied to a particular frequency band for a particular first electrical audio input signal in the frequency domain.
The first noise reduction system may comprise a first beamformer mixing factor configured to mix the first directional signal and one of the first electrical audio input signals providing a first mixed directional signal. The first beamformer mixing factor may be a value between 0 and 1. The first processed signal may be based on the first mixed directional signal.
The first post-filter may be a filter implemented in the frequency domain. Each first filter coefficient may correspond to a first gain value for a particular frequency band in the frequency domain. The first gain value may be used to attenuate or amplify particular frequency bands of the first directional signal. The first gain value may be a multiplicative factor applied to the first electrical audio input signal represented in the frequency domain. The first gain value may be determined based on a gain input/output (IO) map that may resemble the function of the Wiener filter estimator, the log-spectral amplitude estimator, etc. The input to the gain IO map may be based on a determined signal-to-noise ratio (SNR) determined based on the first directional signal. Thus, the gain IO map is configured to provide the first gain value, or the first filter coefficient, based on the first directional signal. The gain IO map may receive a first IO map bias. The first IO map bias may be used to modify curvature of the gain IO map. The first gain IO map bias may be used to modify the input to the first gain IO map (e.g., the estimated signal-to-noise ratio) by offsetting or biasing the input to a lower value or higher value in dependence of the numerical value of the first IO map bias. For example, a positive first IO map bias may result in a positive offsetting of the input to the gain IO map whereas a negative first IO map bias may result in a negative offsetting of the input to the gain IO map. The offsetting may be a scalar value added to the input to the gain IO map. Thus, offsetting of the input to the gain IO map may influence the first gain value, so that a positive offset results in a larger first gain value, and a negative offset results in a smaller first gain value. Hence, the first IO map bias may be used to adjust the aggressiveness of the first post-filter, where aggressiveness may refer to the degree of allowable attenuation or filtering of the first directional signal or first mixed directional signal. The first IO map bias may be based on the first motion bias and/or the first conversation parameter. The first IO map bias may be the first motion bias or the first conversation parameter or a combination of both.
The first noise reduction parameter may be the first beamformer mixing factor. The first noise reduction parameter may be the first gain value determined based on the first motion bias.
The first processed signal may be the first directional signal. The first processed signal may be the first mixed directional signal. The first processing signal may be the first post-filtered signal.
The first motion sensor may be a sensor configured to determine the movement, orientation, or acceleration or a combination thereofof the first hearing aid. The first motion sensor may be an accelerometer, and/or a gyroscope, and/or an inertial measurement unit (IMU). The first motion sensor may be configured to provide a first motion sensor value indicative of movement, and/or orientation, and/or acceleration of the first hearing aid.
The first motion sensor may be configured to determine the first motion bias based on the first motion sensor value. The first motion bias may be a value between 0 and 1 or between -1 and 1. The first motion bias may be a value indicative of movements such as rotation and/or translation of the first hearing aid. In a particular embodiment, if the first motion bias is closer to a value of -1 than 1, the first motion bias is indicative of a significant portion of movements of the first hearing aid over a predefined time-span such as 1 s, 5 s, 10 s, etc. In contrast, if the first motion bias is closer to a value of 1 than -1, the first motion bias is indicative of little movements of the first hearing aid over a predefined time-span such as 1 s, 5 s, 10 s, etc. The first motion sensor may be configured to determine the first motion bias based on a motion input/output (IO) map. The motion IO map may be a function or a look-up table that maps the first motion sensor value to a first motion bias. The motion IO map may be predetermined by a hearing aid developer.
The first conversation detector may comprise a first own voice activity detector. The first own voice activity detector may be configured to detect the presence of a hearing aid user's own voice. The presence of a hearing aid user's own voice may be indicative of a conversation being present. The first own voice activity detector may be configured to provide a first own voice activity value based on the first electrical audio input signal. The first own voice activity value may be a value between 0 and 1 indicating the probability of the presence of the own voice in the first electrical audio input signal.
The first conversation detector may comprise a first directional voice activity detector. The first directional voice activity detector may be configured to detect the presence of a directional voice signal in the frontal half-plane relative to the hearing aid user including the hearing aid user's own voice. The presence of a voice in the frontal half-plane relative to the hearing aid user may be indicative of a conversation being present. The first directional voice activity detector may be configured to provide a first directional voice activity value based on the first electrical audio input signal. The first directional voice activity value may be a value between 0 and 1 indicating the probability of the presence of a directional voice in the first electrical audio input signal.
The first conversation parameter may be a value between 0 and 1. A value close to 1 indicates a high likelihood of the presence of a conversation. A value close to 0 indicates a low likelihood of the presence of a conversation. The first conversation parameter may be based on the first own voice activity value. The first conversation parameter may be based on the first directional voice activity value.
A conversation may be defined as a conversation between the hearing aid user and a speaker of interest to the hearing aid user.
The first hearing aid comprises a first output unit. The first output unit comprises a first loudspeaker. The first loudspeaker is configured to provide a first audible processed sound based on the first processed output signal. The first audible processed sound may be heard by the hearing aid user of the first hearing aid.
The first noise reduction parameter is determined based on the first motion bias. In a particular embodiment, if the first motion bias is low, e.g., close to a value of -1 or a value indicative of movements of the first hearing aid (e.g. caused by head turns), the gain IO map may return a gain close to 1, since it may be desirable to have less noise reduction when the first hearing aid is moving due to, e.g., head turns, which may be indicative of a change in attention. In a particular embodiment, if the first motion bias is high, e.g., close to a value of 1 or a value being indicative of no movements of the first hearing aid (e.g. caused by head being held still), the gain IO map will return a gain close to a value of 0, since it may be desirable to have more noise reduction when the first hearing aid is being held still which may be indicative of a desired focus of attention by the hearing aid user.
In a particular embodiment, the first motion bias may be a value between 0 and 1, where 0 is indicative of little to no movement of the first hearing aid, and 1 is indicative of large amounts of head movements, such as head-turns of at least 10 degrees. The first motion bias may be used for the first beamformer mixing factor. The first motion bias may be used for the first IO map bias.
The first noise reduction parameter is determined based on the first conversation parameter and/or the second conversation parameter. In a particular embodiment, the first conversation parameter is a value between 0 and 1, where 0 represents that no conversation is detected present on the first hearing aid, and 1 represents that a conversation is detected present on the first hearing aid. In a particular embodiment, the second conversation parameter is a value between 0 and 1, where 0 represents that no conversation is detected present on the second hearing aid, and 1 represents that a conversation is detected present on the second hearing aid. Values of the first and second conversation parameters between 0 and 1 are interpreted as the probability that a conversation is detected present on the first and second hearing aids, respectively.
The first IO map bias may be based on the first conversation parameter. The first beamformer mixing factor may be the first noise reduction parameter. The first gain value may be based on the second conversation parameter.
In a particular embodiment, the first IO map bias may be based on the first motion bias, the first conversation parameter, and the second conversation parameter. The first noise reduction system is configured to select the numerically largest conversation parameter of the first conversation parameter and the second conversation parameter, and combine the selected conversation parameter with the first motion bias. The combination may be based on a multiplication of the selected conversation parameter and the first motion bias. The first IO map bias may be based on the combination.
The second noise reduction system may comprise a second beamformer. The second beamformer may be configured to provide a second directional signal based on the plurality of second electrical audio input signals by combining the second electrical audio input signals. The second beamformer may be a delay-and-sum beamformer, or a delay-and-subtract beamformer, or a minimum variance distortionless response (MVDR) beamformer, or any other beamformer. The second noise reduction system may comprise a second post-filter. The second post-filter may be configured to provide a second post-filtered signal based on the second directional signal. The second post-filter may comprise one or more second filter coefficients. The second post-filter may be configured to filter the second directional signal based on the one or more second filter coefficients. The second filter coefficients may be determined based on, for example, the Wiener filter, or the log-spectral amplitude estimator, etc. The second processed signal may be based on the second post-filtered signal.
The second noise reduction system may constitute a digital signal processor that may be a computer processor of the second hearing aid. The second noise reduction system may be a signal processing system that is of the digital signal processor. The second signal processing system may be configured to carry out numerical computations.
The second beamformer may be implemented in the frequency domain. The second beamformer may comprise a beamforming filter for each of the plurality of second electrical audio input signals. Each beamforming filter may comprise a plurality of beamforming filter weights. The second beamformer may be implemented in the frequency domain. Thereby, each beamforming filter coefficient may correspond to a complex value applied to a particular frequency band for a particular second electrical audio input signal in the frequency domain.
The second noise reduction system may comprise a second beamformer mixing factor configured to mix the second directional signal and one of the second electrical audio input signals providing a second mixed directional signal. The second beamformer mixing factor may be a value between 0 and 1. The second processed signal may be based on the second mixed directional signal.
The second post-filter may be a filter implemented in the frequency domain. Each second filter coefficient may correspond to a second gain value in a particular frequency band in the frequency domain. The second gain value may be used to attenuate or amplify particular frequency bands of the second directional signal. The second gain value may be a multiplicative factor applied to the second electrical audio input signal represented in the frequency domain. The second gain value may be determined based on a gain input/output (IO) map that may resemble the function of the Wiener filter estimator, the log-spectral amplitude estimator, etc. The input to the gain IO map may be based on a determined signal-to-noise ratio (SNR) determined based on the second directional signal. Thereby, the gain IO map is configured to provide the second gain value, or the second filter coefficient, based on the second directional signal. The gain IO map may receive a second IO map bias. The second 10 map bias may be used to modify curvature of the gain IO map. The second gain IO map bias may be used to modify the input to the second gain IO map (e.g., the estimated signal-to-noise ratio) by offsetting or biasing the input to a lower value or higher value in dependence of the numerical value of the second IO map bias. For example, a positive second IO map bias may result in a positive offsetting of the input to the gain IO map whereas a negative second IO map bias may result in a negative offsetting of the input to the gain IO map. The offsetting may be a scalar value added to the input to the gain IO map. Thereby, offsetting of the input to the gain IO map may influence the second gain value, so that a positive offset results in a larger second gain value, and a negative offset results in a smaller second gain value. Hence, the second IO map bias may be used to adjust the aggressiveness of the second post-filter, where aggressiveness may refer to the degree of allowable attenuation or filtering of the second directional signal or second mixed directional signal. The second IO map bias may be based on the first motion bias and/or the second conversation parameter. The second IO map bias may be the first motion bias or the second conversation parameter or a combination of both.
The second noise reduction parameter may be the second beamformer mixing factor. The second noise reduction parameter may be the second gain value determined based on the second motion bias.
The second processed signal may be the second directional signal. The second processed signal may be the second mixed directional signal. The second processing signal may be the second post-filtered signal.
The second conversation detector may comprise a second own voice activity detector. The second own voice activity detector may be configured to detect the presence of a hearing aid user's own voice. The presence of a hearing aid user's own voice may be indicative of a conversation being present. The second own voice activity detector may be configured to provide a second own voice activity value based on the second electrical audio input signal. The second own voice activity value may be a value between 0 and 1 indicating the probability of the presence of the own voice in the second electrical audio input signal.
The second conversation detector may comprise a second directional voice activity detector. The second directional voice activity detector may be configured to detect the presence of a directional voice signal in the frontal half-plane relative to the hearing aid user including the hearing aid user's own voice. The presence of a voice in the frontal half-plane relative to the hearing aid user may be indicative of a conversation being present. The second directional voice activity detector may be configured to provide a second directional voice activity value based on the second electrical audio input signal. The second directional voice activity value may be a value between 0 and 1 indicating the probability of the presence of a directional voice in the second electrical audio input signal.
The second conversation parameter may be a value between 0 and 1. A value close to 1 indicates a high likelihood of the presence of a conversation. A value close to 0 indicates a low likelihood of the presence of a conversation. The second conversation parameter may be based on the second own voice activity value. The second conversation parameter may be based on the second directional voice activity value.
A conversation may be defined as a conversation between the hearing aid user and a speaker of interest to the hearing aid user.
The second hearing aid comprises a second output unit. The second output unit comprises a second loudspeaker. The second loudspeaker is configured to provide a second audible processed sound based on the second processed output signal. The second audible processed sound may be heard by the hearing aid user of the second hearing aid.
The second noise reduction parameter is determined based on the first motion bias. In a particular embodiment, if the first motion bias is low, e.g., close to a value of -1 or a value indicative of movements of the first hearing aid (e.g. caused by head turns), the gain IO map will return a gain close to a value of 1, since it may be desirable to have less noise reduction when the first hearing aid is moving due to, e.g., head turns, which may be indicative of a change of attention. In a particular embodiment, if the first motion bias is high, e.g., close to a value of 1 or a value being indicative of no movements of the first hearing aid (e.g. caused by head being held still), the gain IO map will return a gain close to 0, since it may be desirable to have more noise reduction when the first hearing aid is being held still of which it may be indicative of a desired focus of attention by the hearing aid user. The first motion bias may be wirelessly transmitted from the first hearing aid to the second hearing aid. Movements in the first hearing aid may be correlated with movements in the second hearing aid. In some cases, it may be desirable to use the same motion bias to determine both the first noise reduction parameter and the second noise reduction parameter to ensure synchronization between the noise reduction parameters of the hearing aids.
In a particular embodiment, the first motion bias may be a value between 0 and 1, where 0 is indicative of little to no movements of the first hearing aid, and 1 is indicative of large amounts of head movements, such as head-turns of at least 10 degrees. The first motion bias may be used for the second beamformer mixing factor. The first motion bias may be used for the second IO map bias.
The first noise reduction parameter is determined based on the first conversation parameter and/or the second conversation parameter. In a particular embodiment, the first conversation parameter is a value between 0 and 1, where 0 represents that no conversation is detected present on the first hearing aid, and 1 represents that a conversation is detected present on the first hearing aid. In a particular embodiment, the second conversation parameter is a value between 0 and 1, where 0 represents that no conversation is detected present on the second hearing aid, and 1 represents that a conversation is detected present on the second hearing aid. Values of the first and second conversation parameters between 0 and 1 are interpreted as the probability that a conversation is detected present on the first and second hearing aids, respectively.
The first IO map bias may be based on the first conversation parameter. The first beamformer mixing factor may be the first noise reduction parameter. The first gain value may be based on the second conversation parameter.
In a particular embodiment, the first IO map bias may be based on the first motion bias, the first conversation parameter, and the second conversation parameter. The first noise reduction system is configured to select the numerically largest conversation parameter of the first conversation parameter and the second conversation parameter, and combine the selected conversation parameter with the first motion bias. The combination may be based on a multiplication of the selected conversation parameter and the first motion bias. The first IO map bias may be based on the combination.
The second hearing aid may comprise a second motion sensor. The second motion sensor may be configured to provide a second motion bias. The second noise reduction parameter may be determined based on the first and second motion biases. The second noise reduction parameter may be determined based on the first conversation parameter and/or the second conversation parameter.
The second motion sensor may be a sensor configured to determine the movement, orientation, acceleration or a combination thereof of the second hearing aid. The second motion sensor may be an accelerometer, and/or a gyroscope, and/or an inertial measurement unit (IMU). The second motion sensor may be configured to provide a second motion sensor value indicative of movement, and/or orientation, and/or acceleration of the second hearing aid.
The second motion sensor may be configured to determine the second motion bias based on the second motion sensor value. The second motion bias may be a value between 0 and 1 or between -1 and 1. The second motion bias may be a value indicative of movements such as rotation and/or translation of the second hearing aid. In a particular embodiment, if the second motion bias is closer to a value of -1 than 1, the second motion bias is indicative of a significant portion of movements of the second hearing aid over a predefined time-span such as 1 s, 5 s, 10 s, etc. In contrast, if the second motion bias is closer to a value of 1 than -1, the second motion bias is indicative of little movement of the second hearing aid over a predefined time-span such as 1 s, 5 s, 10 s, etc. The second motion sensor may be configured to determine the second motion bias based on a motion input/output (IO) map. The motion IO map may be a function or a look-up table that maps the second motion sensor value to a second motion bias. The motion IO map may be predetermined by a hearing aid developer.
The second noise reduction parameter may be determined based on the first and/or second motion biases. The second noise reduction parameter is configured to use the first motion bias if a stable wireless communication link is established between the first hearing aid and the second hearing aid. The second noise reduction parameter is configured to use the second motion bias if no wireless communication link is established or if the wireless communication link is unstable.
Thereby, one advantage of the present disclosure is that the second hearing aid can flexibly determine its noise reduction behavior based on both its own motion sensor and the motion sensor of the first hearing aid, depending on the quality of the wireless connection. For example, when a stable wireless link is available, the second hearing aid can synchronize with the first hearing aid by using the first motion bias, ensuring consistent noise reduction across both ears. Conversely, if the connection is unstable, the second hearing aid can fall back on its own motion bias, maintaining robust and context-aware performance. This dual-source approach enhances reliability and user experience, especially in dynamic or noisy environments.
The second hearing aid may be configured to determine a wireless signal quality of the wireless communication between the first and second hearing aids.
The first hearing aid may be configured to determine a second wireless signal quality of the wireless communication between the first and second hearing aids.
The wireless signal quality may be indicative of whether a stable wireless communication link is established between the first hearing aid and the second hearing aid. The wireless signal quality may be a value between 0 and 1 where a value of 0 may indicate that the wireless communication link is unstable or not present. A value of 1 may indicate that the wireless communication link is stable. A value between 0 and 1 may indicate a score of the stability or quality of the wireless communication link.
The second noise reduction parameter may be determined based on the first motion bias if the wireless signal quality is equal to or above a threshold. The second noise reduction parameter may be determined based on the second motion bias if the wireless signal quality is below the threshold.
The threshold may be a value between 0 and 1. The threshold may be a value in the same numerical range as the numerical range of the wireless signal quality. The threshold may be predetermined by a hearing aid developer.
The second noise reduction parameter may be determined based on a first combination of the first motion bias and the second motion bias. The first combination may be an average of the first motion bias and the second motion bias. The first combination may be based on smoothing towards the first motion bias or the second motion bias. If the wireless signal quality is equal to or above the threshold, the first combination may smooth towards the first motion bias. If the wireless signal quality is below the threshold, the first combination may smooth towards the second motion bias. The smoothing may be based on a low-pass filter with a predetermined smoothing factor, e.g., a value between 0 and 1. The first combination may be based on stepping towards the first motion bias or the second motion bias. If the wireless signal quality is above the equal to or above the threshold, the first combination may step towards the first motion bias. If the wireless signal quality is below the threshold, the first combination may step towards the second motion bias. The stepping towards the first motion bias or the second motion bias may be based on a predetermined step size, e.g., 0.01, 0.05, 0.1, etc.
Thereby, one advantage of the present disclosure is the adjustment of the second noise reduction parameter based on the quality of the wireless connection, allowing the system to prioritize either the first or second motion bias. For example, when the wireless signal quality is equal to or above a predefined threshold, the second hearing aid can align its behavior with the first hearing aid by favoring the first motion bias. If the connection is weak or lost, it can instead rely on its own second motion bias. This adaptive strategy, optionally enhanced through smoothing or stepping mechanisms, ensures a natural transitions and consistent noise reduction performance, even in fluctuating connectivity conditions.
The second noise reduction parameter may be determined based on the first conversation parameter and/or the second conversation parameter if the wireless signal quality is equal to or above a threshold. The second noise reduction parameter may be determined based on the second conversation parameter if the wireless signal quality is below the threshold.
The second noise reduction parameter may be determined based on a second combination of the first conversation parameter and the second motion bias. The second combination may be an average of the first conversation parameter and the second motion bias. The second combination may be based on smoothing towards the first conversation parameter or the second motion bias. If the wireless signal quality is equal to or above the threshold, the second combination may smooth towards the first motion bias. If the wireless signal quality is below the threshold, the second combination may smooth towards the second motion bias. The smoothing may be based on a low-pass filter with a predetermined smoothing factor, e.g., a value between 0 and 1. The second combination may be based on stepping towards the first conversation parameter or the second motion bias. If the wireless signal quality is above the equal to or above the threshold, the second combination may step towards the first motion bias. If the wireless signal quality is below the threshold, the second combination may step towards the second motion bias. The stepping towards the first motion bias or the second motion bias may be based on a predetermined step size, e.g., 0.01, 0.05, 0.1, etc.
Thereby, one advantage of the present disclosure is the ability of the second hearing aid to combine conversation awareness and motion context depending on the stability of the wireless connection. For example, when the wireless signal quality is equal to or above a threshold, the second noise reduction parameter can incorporate the first conversation parameter, enabling synchronized, binaural exchange of conversational cues. If the connection is unstable, the system can fall back on the second conversation parameter and local motion data. This adaptive combination, whether through averaging, smoothing, or stepping, ensures that the hearing aid system maintains good speech clarity and noise suppression, even under varying connectivity conditions.
If the wireless signal quality is below the threshold, the first noise reduction parameter may be determined based on the first motion bias and the first conversation parameter. If the wireless signal quality is below the threshold, the second noise reduction parameter may be determined based on the second motion bias and the second conversation parameter.
Thereby, one advantage of the present disclosure is a fallback mechanism that allows each hearing aid to operate independently using local motion and conversation data when the wireless connection is unstable. For example, if the wireless signal quality drops below a predefined threshold, the first and second hearing aids can each determine their respective noise reduction parameters based on their own motion and conversation inputs. This ensures uninterrupted and context-aware noise reduction performance, even in environments where wireless communication between the devices is degraded or temporarily lost.
The first and second noise reduction parameters may be determined based on the first conversation parameter if the first conversation parameter is equal to or greater than the second conversation parameter. The first and second noise reduction parameters may be determined based on the second conversation parameter if the second conversation parameter is greater than the first conversation parameter.
Thereby, one advantage of the present disclosure is the selection of the most reliable conversation parameter, either from the first or second hearing aid, based on which has the higher value, thereby minimizing the impact of the head shadow effect. For example, if one hearing aid detects a stronger conversational signal than the other, both devices can align their noise reduction behavior to that signal, ensuring more accurate speech enhancement and a consistent auditory experience for the user, regardless of the speaker's position relative to the head.
If the wireless signal quality is below the threshold, the first noise reduction parameter may be determined based on the first motion bias. If the wireless signal quality is below the threshold, the first noise reduction parameter may be determined based on the first conversation parameter. If the wireless signal quality is below the threshold, the second noise reduction parameter may be determined based on the first motion bias. If the wireless signal quality is below the threshold, the second noise reduction parameter may be determined based on the second conversation parameter.
The first noise reduction system may comprise a first beamformer. The second noise reduction system may comprise a second beamformer. The first noise reduction parameter may be used to adjust the first beamformer. The second noise reduction parameter may be used to adjust the second beamformer.
In a particular embodiment, the second noise reduction parameter may be used to adjust the second beamformer by adjusting the beamformer mixing factor.
The first noise reduction system may comprise a first post-filter. The second noise reduction system may comprise a second post-filter. The first noise reduction parameter may be used to adjust the first post-filter. The second noise reduction parameter may be used to adjust the second post-filter.

A hearing aid:

The hearing aid may be adapted to provide a frequency dependent gain and/or a level dependent compression and/or a transposition (with or without frequency compression) of one or more frequency ranges to one or more other frequency ranges, e.g. to compensate for a hearing impairment of a user. The hearing aid may comprise a signal processor for enhancing the input signals and providing a processed output signal.
The hearing aid may comprise an output unit for providing a stimulus perceived by the user as an acoustic signal based on a processed electric signal. The output unit may a vibrator of a bone conducting hearing aid. The output unit may comprise an output transducer. The output transducer may comprise a receiver (loudspeaker) for providing the stimulus as an acoustic signal to the user (e.g. in an acoustic (air conduction based) hearing aid). The output transducer may comprise a vibrator for providing the stimulus as mechanical vibration of a skull bone to the user (e.g. in a bone-attached or bone-anchored hearing aid). The output unit may (additionally or alternatively) comprise a (e.g. wireless) transmitter for transmitting sound picked up-by the hearing aid to another device, e.g. a far-end communication partner (e.g. via a network, e.g. in a telephone mode of operation).
The hearing aid may comprise an input unit for providing an electric input signal representing sound. The input unit may comprise an input transducer, e.g. a microphone, for converting an input sound to an electric input signal. The input unit may comprise a wireless receiver for receiving a wireless signal comprising or representing sound and for providing an electric input signal representing said sound.
The wireless receiver and/or transmitter may e.g. be configured to receive and/or transmit an electromagnetic signal in the radio frequency range (3 kHz to 300 GHz). The wireless receiver and/or transmitter may e.g. be configured to receive and/or transmit an electromagnetic signal in a frequency range of light (e.g. infrared light 300 GHz to 430 THz, or visible light, e.g. 430 THz to 770 THz).
The hearing aid may comprise a directional microphone system adapted to spatially filter sounds from the environment, and thereby enhance a target acoustic source among a multitude of acoustic sources in the local environment of the user wearing the hearing aid. The directional system may be adapted to detect (such as adaptively detect) from which direction a particular part of the microphone signal originates. This can be achieved in various different ways as e.g. described in the prior art. In hearing aids, a microphone array beamformer is often used for spatially attenuating background noise sources. The beamformer may comprise a linear constraint minimum variance (LCMV) beamformer. Many beamformer variants can be found in literature. The minimum variance distortion-less response (MVDR) beamformer is widely used in microphone array signal processing. Ideally the MVDR beamformer keeps the signals from the target direction (also referred to as the look direction) unchanged, while attenuating sound signals from other directions maximally. The generalized sidelobe canceller (GSC) structure is an equivalent representation of the MVDR beamformer offering computational and numerical advantages over a direct implementation in its original form.
Most sound signal sources (except the user's own voice) are located far way from the user compared to dimensions of the hearing aid, e.g. a distance d_mic between two microphones of a directional system. A typical microphone distance in a hearing aid is of the order 10 mm. A minimum distance of a sound source of interest to the user (e.g. sound from the user's mouth or sound from an audio delivery device) is of the order of 0.1 m (> 10 d_mic). For such minimum distances, the hearing aid (microphones) would be in the acoustic near-field of the sound source and a difference in level of the sound signals impinging on respective microphones may be significant. A typical distance for a communication partner is more than 1 m (>100 d_mic). The hearing aid (microphones) would be in the acoustic far-field of the sound source and a difference in level of the sound signals impinging on respective microphones is insignificant. The difference in time of arrival of sound impinging in the direction of the microphone axis (e.g. the front or back of a normal hearing aid) is ΔT= d_mic/v_sound=0.01/343 [s]=29 µs, where v_sound is the speed of sound in air at 20°C (343 m/s).
The hearing aid may comprise antenna and transceiver circuitry allowing a wireless link to an entertainment device (e.g. a TV-set), a communication device (e.g. a telephone), a wireless microphone, a separate (external) processing device, or another hearing aid, etc. The hearing aid may thus be configured to wirelessly receive a direct electric input signal from another device. Likewise, the hearing aid may be configured to wirelessly transmit a direct electric output signal to another device. The direct electric input or output signal may represent or comprise an audio signal and/or a control signal and/or an information signal.
In general, a wireless link established by antenna and transceiver circuitry of the hearing aid can be of any type. The wireless link may be a link based on near-field communication, e.g. an inductive link based on an inductive coupling between antenna coils of transmitter and receiver parts. The wireless link may be based on far-field, electromagnetic radiation. Preferably, frequencies used to establish a communication link between the hearing aid and the other device is below 70 GHz, e.g. located in a range from 50 MHz to 70 GHz, e.g. above 300 MHz, e.g. in an ISM range above 300 MHz, e.g. in the 900 MHz range or in the 2.4 GHz range or in the 5.8 GHz range or in the 60 GHz range (ISM=Industrial, Scientific and Medical, such standardized ranges being e.g. defined by the International Telecommunication Union, ITU). The wireless link may be based on a standardized or proprietary technology. The wireless link may be based on Bluetooth technology (e.g. Bluetooth Low-Energy technology, e.g. LE audio), or Ultra WideBand (UWB) technology.
The hearing aid may be constituted by or form part of a portable (i.e. configured to be wearable) device, e.g. a device comprising a local energy source, e.g. a battery, e.g. a rechargeable battery. The hearing aid may e.g. be a low weight, easily wearable, device, e.g. having a total weight less than 100 g, such as less than 20 g, such as less than 5 g.
The hearing aid may comprise a "forward" (or 'signal') path for processing an audio signal between an input and an output of the hearing aid. A signal processor may be located in the forward path. The signal processor may be adapted to provide a frequency dependent gain according to a user's particular needs (e.g. hearing impairment). The hearing aid may comprise an 'analysis' path comprising functional components for analyzing signals and/or controlling processing of the forward path. Some or all signal processing of the analysis path and/or the forward path may be conducted in the frequency domain, in which case the hearing aid comprises appropriate analysis and synthesis filter banks. Some or all signal processing of the analysis path and/or the forward path may be conducted in the time domain.
An analogue electric signal representing an acoustic signal may be converted to a digital audio signal in an analogue-to-digital (AD) conversion process, where the analogue signal is sampled with a predefined sampling frequency or rate f_s, f_s being e.g. in the range from 8 kHz to 48 kHz (adapted to the particular needs of the application) to provide digital samples x_n (or x[n]) at discrete points in time t_n (or n), each audio sample representing the value of the acoustic signal at t_n by a predefined number N_b of bits, N_b being e.g. in the range from 1 to 48 bits, e.g. 24 bits. Each audio sample is hence quantized using N_b bits (resulting in 2^Nb different possible values of the audio sample). A digital sample x has a length in time of 1/f_s, e.g. 50 µs, for f_s = 20 kHz. A number of audio samples may be arranged in a time frame. A time frame may comprise 64 or 128 audio data samples. Other frame lengths may be used depending on the practical application.
The hearing aid may comprise an analogue-to-digital (AD) converter to digitize an analogue input (e.g. from an input transducer, such as a microphone) with a predefined sampling rate, e.g. 20 kHz. The hearing aids may comprise a digital-to-analogue (DA) converter to convert a digital signal to an analogue output signal, e.g. for being presented to a user via an output transducer.
The hearing aid, e.g. the input unit, and or the antenna and transceiver circuitry may comprise a transform unit for converting a time domain signal to a signal in the transform domain (e.g. frequency domain or Laplace domain, Z transform, wavelet transform, etc.). The transform unit may be constituted by or comprise a TF-conversion unit for providing a time-frequency representation of an input signal. The time-frequency representation may comprise an array or map of corresponding complex or real values of the signal in question in a particular time and frequency range. The TF conversion unit may comprise a filter bank for filtering a (time varying) input signal and providing a number of (time varying) output signals each comprising a distinct frequency range of the input signal. The TF conversion unit may comprise a Fourier transformation unit (e.g. a Discrete Fourier Transform (DFT) algorithm, or a Short Time Fourier Transform (STFT) algorithm, or similar) for converting a time variant input signal to a (time variant) signal in the (time-)frequency domain. The frequency range considered by the hearing aid from a minimum frequency f_min to a maximum frequency f_max may comprise a part of the typical human audible frequency range from 20 Hz to 20 kHz, e.g. a part of the range from 20 Hz to 12 kHz. Typically, a sample rate f_s is larger than or equal to twice the maximum frequency f_max, f_s ≥ 2f_max. A signal of the forward and/or analysis path of the hearing aid may be split into a number NI of frequency bands (e.g. of uniform width), where NI is e.g. larger than 5, such as larger than 10, such as larger than 50, such as larger than 100, such as larger than 500, at least some of which are processed individually. The hearing aid may be adapted to process a signal of the forward and/or analysis path in a number NP of different frequency channels (NP ≤ NI). The frequency channels may be uniform or non-uniform in width (e.g. increasing in width with frequency), overlapping or non-overlapping.
The hearing aid may be configured to operate in different modes, e.g. a normal mode and one or more specific modes, e.g. selectable by a user, or automatically selectable. A mode of operation may be optimized to a specific acoustic situation or environment, e.g. a communication mode, such as a telephone mode. A mode of operation may include a low-power mode, where functionality of the hearing aid is reduced (e.g. to save power), e.g. to disable wireless communication, and/or to disable specific features of the hearing aid.
The hearing aid may comprise a number of detectors configured to provide status signals relating to a current physical environment of the hearing aid (e.g. the current acoustic environment), and/or to a current state of the user wearing the hearing aid, and/or to a current state or mode of operation of the hearing aid. Alternatively or additionally, one or more detectors may form part of an external device in communication (e.g. wirelessly) with the hearing aid. An external device may e.g. comprise another hearing aid, a remote control, and audio delivery device, a telephone (e.g. a smartphone), an external sensor, etc.
One or more of the number of detectors may operate on the full band signal (time domain). One or more of the number of detectors may operate on band split signals ((time-) frequency domain), e.g. in a limited number of frequency bands.
The number of detectors may comprise a level detector for estimating a current level of a signal of the forward path. The detector may be configured to decide whether the current level of a signal of the forward path is above or below a given (L-)threshold value. The level detector operates on the full band signal (time domain). The level detector operates on band split signals ((time-) frequency domain).
The hearing aid may comprise a voice activity detector (VAD) for estimating whether or not (or with what probability) an input signal comprises a voice signal (at a given point in time). A voice signal may in the present context be taken to include a speech signal from a human being. It may also include other forms of utterances generated by the human speech system (e.g. singing). The voice activity detector unit may be adapted to classify a current acoustic environment of the user as a VOICE or NO-VOICE environment. This has the advantage that time segments of the electric microphone signal comprising human utterances (e.g. speech) in the user's environment can be identified, and thus separated from time segments only (or mainly) comprising other sound sources (e.g. artificially generated noise). The voice activity detector may be adapted to detect as a VOICE also the user's own voice. Alternatively, the voice activity detector may be adapted to exclude a user's own voice from the detection of a VOICE.
The hearing aid may comprise an own voice detector for estimating whether or not (or with what probability) a given input sound (e.g. a voice, e.g. speech) originates from the voice of the user of the system. A microphone system of the hearing aid may be adapted to be able to differentiate between a user's own voice and another person's voice and possibly from NON-voice sounds.
The number of detectors may comprise a movement detector, e.g. an acceleration sensor. The movement detector may be configured to detect movement of the user's facial muscles and/or bones, e.g. due to speech or chewing (e.g. jaw movement) and to provide a detector signal indicative thereof.
The hearing aid may comprise a classification unit configured to classify the current situation based on input signals from (at least some of) the detectors, and possibly other inputs as well. In the present context 'a current situation' may be taken to be defined by one or more of

a) the physical environment (e.g. including the current electromagnetic environment, e.g. the occurrence of electromagnetic signals (e.g. comprising audio and/or control signals) intended or not intended for reception by the hearing aid, or other properties of the current environment than acoustic);
b) the current acoustic situation (input level, feedback, etc.), and
c) the current mode or state of the user (movement, temperature, cognitive load, etc.);
d) the current mode or state of the hearing aid (program selected, time elapsed since last user interaction, etc.) and/or of another device in communication with the hearing aid.

The classification unit may be based on or comprise a neural network, e.g. a recurrent neural network, e.g. a trained neural network.
The hearing aid may comprise an acoustic (and/or mechanical) feedback control (e.g. suppression) or echo-cancelling system. Adaptive feedback cancellation has the ability to track feedback path changes over time. It is typically based on a linear time invariant filter to estimate the feedback path but its filter weights are updated over time. The filter update may be calculated using stochastic gradient algorithms, including some form of the Least Mean Square (LMS) or the Normalized LMS (NLMS) algorithms. They both have the property to minimize the error signal in the mean square sense with the NLMS additionally normalizing the filter update with respect to the squared Euclidean norm of some reference signal.
The hearing aid may further comprise other relevant functionality for the application in question, e.g. compression, noise reduction, etc.
The hearing aid may comprise a hearing instrument, e.g. a hearing instrument adapted for being located at the ear or fully or partially in the ear canal of a user.

A method:

In an aspect, a method for providing a first audible output signal and a second audible output signal comprises wirelessly communicating between a first hearing aid and a second hearing aid. The method comprises providing, by the first hearing aid comprising a first input unit, a first electrical audio input signal. The method comprises attenuating, by the first hearing aid comprising a first noise reduction system comprising a first noise reduction parameter, noise in the first electrical audio input signal. The method comprises providing, by the first noise reduction system, a first processed signal based on the first electrical audio input signal. The method comprises providing, by the first hearing aid comprising a first motion sensor, a first motion bias of the first hearing aid. The method comprises providing, by the first hearing aid comprising a first conversation detector, a first conversation parameter indicative of the likelihood of a conversation in the first electrical audio input signal based on the first electrical audio input signal. The method comprises providing, by the first hearing aid comprising a first output unit, a first audible output signal based on the first processed signal. The method comprises providing, by the second hearing aid comprising second input unit, a second electrical audio input signal. The method comprises attenuating, by the second hearing aid comprising a second noise reduction system comprising a second noise reduction parameter, noise in the second electrical audio input signal. The method comprises providing, by the second noise reduction system, a second processed signal based on the second electrical audio input signal. The method comprises providing, by the second hearing aid comprising a second conversation detector, a second conversation parameter indicative of the likelihood of a conversation in the second electrical audio input signal based on the second electrical audio input signal. The method comprises providing, by the second hearing aid comprising a second output unit, a second audible output signal based on the second processed signal. The method comprises determining the first noise reduction parameter based on the first motion bias and the first or second conversation parameter, and determining the second noise reduction parameter based on the first motion bias and the first or second conversation parameter.
It is intended that some or all of the structural features of the device described above, in the 'detailed description of embodiments' or in the claims can be combined with embodiments of the method, when appropriately substituted by a corresponding process and vice versa. Embodiments of the method have the same advantages as the corresponding devices.

Definitions:

In the present context, a hearing aid, e.g. a hearing instrument, refers to a device, which is adapted to improve, augment and/or protect the hearing capability of a user by receiving acoustic signals from the user's surroundings, generating corresponding audio signals, possibly modifying the audio signals and providing the possibly modified audio signals as audible signals to at least one of the user's ears. Such audible signals may e.g. be provided in the form of acoustic signals radiated into the user's outer ears and/or acoustic signals transferred as mechanical vibrations to the user's inner ears through the bone structure of the user's head and/or through parts of the middle ear.
The hearing aid may be configured to be worn in any known way, e.g. as a unit arranged behind the ear with a tube leading radiated acoustic signals into the ear canal or with an output transducer, e.g. a loudspeaker, arranged close to or in the ear canal, as a unit entirely or partly arranged in the pinna and/or in the ear canal, as a unit, e.g. a vibrator, attached to a fixture implanted into the skull bone, etc. The hearing aid may comprise a single unit or several units communicating (e.g. acoustically, electrically or optically) with each other. The loudspeaker may be arranged in a housing together with other components of the hearing aid, or may be an external unit in itself (possibly in combination with a flexible guiding element, e.g. a dome-like element).
A hearing aid may be adapted to a particular user's needs, e.g. a hearing impairment. A configurable signal processing circuit of the hearing aid may be adapted to apply a frequency and level dependent compressive amplification of an input signal. A customized frequency and level dependent gain (amplification or compression) may be determined in a fitting process by a fitting system based on a user's hearing data, e.g. an audiogram, using a fitting rationale (e.g. adapted to speech). The frequency and level dependent gain may e.g. be embodied in processing parameters, e.g. uploaded to the hearing aid via an interface to a programming device (fitting system), and used by a processing algorithm executed by the configurable signal processing circuit of the hearing aid.
A 'hearing system' refers to a system comprising one or two hearing aids, and a 'binaural hearing system' refers to a system comprising two hearing aids and being adapted to cooperatively provide audible signals to both of the user's ears. Hearing systems or binaural hearing systems may further comprise one or more 'auxiliary devices', which communicate with the hearing aid(s) and affect and/or benefit from the function of the hearing aid(s). Such auxiliary devices may include at least one of a remote control, a remote microphone, an audio gateway device, an entertainment device, e.g. a music player, a wireless communication device, e.g. a mobile phone (such as a smartphone) or a tablet or another device, e.g. comprising a graphical interface. Hearing aids, hearing systems or binaural hearing systems may e.g. be used for compensating for a hearing-impaired person's loss of hearing capability, augmenting or protecting a normal-hearing person's hearing capability and/or conveying electronic audio signals to a person. Hearing aids or hearing systems may e.g. form part of or interact with public-address systems, active ear protection systems, handsfree telephone systems, car audio systems, entertainment (e.g. TV, music playing or karaoke) systems, teleconferencing systems, classroom amplification systems, etc.
The invention is set out in the appended set of claims.

BRIEF DESCRIPTION OF DRAWINGS

The aspects of the disclosure may be best understood from the following detailed description taken in conjunction with the accompanying figures. The figures are schematic and simplified for clarity, and they just show details to improve the understanding of the claims, while other details are left out. Throughout, the same reference numerals are used for identical or corresponding parts. The individual features of each aspect may each be combined with any or all features of the other aspects. These and other aspects, features and/or technical effect will be apparent from and elucidated with reference to the illustrations described hereinafter in which:

FIG. 1 schematically shows a first exemplary embodiment of a hearing aid system according to the present disclosure.
FIG. 2 schematically shows a second exemplary embodiment of a hearing aid system according to the present disclosure.
FIG. 3 schematically shows an example embodiment of a method according to the present disclosure.

The figures are schematic and simplified for clarity, and they just show details which are essential to the understanding of the disclosure, while other details are left out. Throughout, the same reference signs are used for identical or corresponding parts.
Further scope of applicability of the present disclosure will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the disclosure, are given by way of illustration only. Other embodiments may become apparent to those skilled in the art from the following detailed description.

DETAILED DESCRIPTION OF EMBODIMENTS

The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. Several aspects of the apparatus and methods are described by various blocks, functional units, modules, components, circuits, steps, processes, algorithms, etc. (collectively referred to as "elements"). Depending upon particular application, design constraints or other reasons, these elements may be implemented using electronic hardware, computer program, or any combination thereof.
The electronic hardware may include micro-electronic-mechanical systems (MEMS), integrated circuits (e.g. application specific), microprocessors, microcontrollers, digital signal processors (DSPs), field programmable gate arrays (FPGAs), programmable logic devices (PLDs), gated logic, discrete hardware circuits, printed circuit boards (PCB) (e.g. flexible PCBs), and other suitable hardware configured to perform the various functionality described throughout this disclosure, e.g. sensors, e.g. for sensing and/or registering physical properties of the environment, the device, the user, etc. Computer program shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.
The present application relates to the field of hearing aid systems.
FIG. 1 shows an exemplary block diagram of a first example hearing aid system according to the present disclosure. The hearing aid system comprises a first hearing aid HA1 and a second hearing aid HA2 configured to wirelessly communicate with one another. The first hearing aid HA1 comprises a first input unit IN1 configured to provide a first electrical audio input signal 101. The first hearing aid HA1 comprises a first noise reduction system NRS1 comprising a first noise reduction parameter configured to attenuate noise in the first electrical audio input signal 101 and for providing a first processed signal 102 based on the first electrical audio input signal 101. The first hearing aid HA1 comprises a first motion sensor MS1 configured to provide a first motion bias 103 of the first hearing aid HA1. The first hearing aid HA1 comprises a first conversation detector CD1 configured to provide a first conversation parameter 104 indicative of the likelihood of a conversation in the first electrical audio input signal based on the first electrical audio input signal 101. The first hearing aid HA1 comprises a first output unit OUT1 configured to provide a first audible output signal 105 based on the first processed signal 102.
The hearing aid system comprises a second hearing aid HA2 comprising a second input unit IN2 configured to provide a second electrical audio input signal 201. The second hearing aid HA2 comprises a second noise reduction system NRS2 comprising a second noise reduction parameter configured to attenuate noise in the second electrical audio input signal 201 and for providing a second processed signal 202 based on the second electrical audio input signal 201. The second hearing aid HA2 comprises a second conversation detector CD2 configured to provide a second conversation parameter 204 indicative of the likelihood of a conversation in the second electrical audio input signal based on the second electrical audio input signal 201. The second hearing aid HA2 comprises a second output unit OUT2 configured to provide a second audible output signal 205 based on the second processed signal.
The first noise reduction parameter is determined based on the first motion bias 103 and either the first conversation parameter 104 or second conversation parameter 204, and the second noise reduction parameter is determined based on the first motion bias 103, and the first conversation parameter 104 or the second conversation parameter 204.
FIG. 2 shows an exemplary block diagram of a first example hearing aid system according to the present disclosure. The hearing aid system comprises a first hearing aid HA1 and a second hearing aid HA2 configured to wirelessly communicate with one another. The first and second hearing aids may for example be based on a behind-the-ear hearing aid, in-the-ear hearing aid, receiver-in-the-ear hearing aid. The first hearing aid may be placed on the left ear of the hearing aid user and the second hearing aid may be placed on the right ear of the hearing aid user. However, in some other embodiments, it may be the opposite.
The first hearing aid HA1 comprises a first input unit IN1 configured to provide a first electrical audio input signal 301. The first input unit IN1 may comprise a microphone or a plurality of microphones configured to pick-up sound. The microphone may be on the first hearing aid. The first input unit may comprise an analog-to-digital converter (ADC) for sampling the electrical signal provided by the microphone.
The first hearing aid HA1 comprises a first noise reduction system NRS1 comprising a first noise reduction parameter configured to attenuate noise in the first electrical audio input signal 301 and for providing a first processed signal 302 based on the first electrical audio input signal 301. The first electrical audio input signal 301 is represented in the frequency domain (or time-frequency domain) using an analysis filter bank (e.g., based on the discrete Fourier transform or the short-time Fourier transform) but may in some other embodiments be represented in the time-domain. In the frequency domain, the first electrical audio input signal 301 comprises a plurality of frequency band signals. The first noise reduction system NRS1 may comprise a first beamformer BF1 if the first noise reduction system NRS1 receives a plurality of first electrical audio input signals 301, for example, if the first input unit IN1 comprises a plurality of microphones. If the first hearing aid HA1 comprises only one microphone or if only one microphone is enabled or non-defective, the first beamformer BF1 may be bypassed. The first beamformer BF1 may be configured to combine the plurality of first electrical audio input signals 301 and provide a first beamformed signal. The first beamformer BF1 may for example be a delay-and-sum beamformer or a minimum variance distortionless response (MVDR) beamformer. The beamformer coefficients of the first beamformer BF1 may be determined during noise-only segments where the target speaker (i.e., the conversational partner or the desired speaker) is silent. Noise-only time segments may be determined by a voice activity detector constituting the first noise reduction system NRS1. The first noise reduction system NRS1 comprises a first post-filter PF1. The first post-filter PF1 may be a filter configured to gain or attenuate particular parts of the frequency spectrum of the first beamformed signal or the first electrical audio input signal 301. The first post-filter PF1 comprises a first gain input-output map configured to provide a first gain value of a frequency band signal of the first electrical audio input signal 301. The first gain values are applied by multiplication on the frequency band signals of the first beamformed signal or the first electrical audio input signal 301. The first gain input-output map is a function that relates the input to the first gain input-output map to one or more gain values constituting the first post-filter PF1. In this particular embodiment, the input to the first gain input-output map is based on the first beamformed signal. For example, the input to the first gain input-output map is based on a first estimated signal-to-noise ratio by a first signal-to-noise estimator constituting the first noise reduction system NRS1 plus a bias value based on a motion bias and/or a conversation parameter. The bias value constitutes the first noise reduction parameter in this particular embodiment. The first signal-to-noise ratio estimator is configured to determine the first signal-to-noise ratio based on the first electrical audio input signal 301. However, in other embodiments, the input to the first gain input-output map may for example be based on a noise estimate determined by the first noise reduction system NRS1.
The first hearing aid HA1 comprises a first motion sensor MS1 configured to provide a first motion bias 303 of the first hearing aid HA1. The first motion sensor MS1 is in this particular embodiment an accelerometer, but could be any other sensor that can be configured to provide a measurement of acceleration, or orientation, or movements. The first noise reduction system is configured to receive the first motion bias. The first motion sensor MS1 is configured to measure a first sensor value indicative of acceleration, orientation, or movements. The first motion sensor MS1 is configured to determine a first motion bias 303 based on the first sensor value. The first sensor value may in principle be a three-dimensional value, i.e., one value for each x-, y-, and z-axis. The first motion sensor MS1 is configured to map the first sensor value to a value between -1 and 1 indicative of whether the hearing aid user is likely moving the head (e.g., a first motion bias close to -1) or whether the hearing aid user is likely holding the head still (e.g., a first motion bias close to 1).
The first hearing aid HA1 comprises a first conversation detector CD1 configured to provide a first conversation parameter 304 indicative of the likelihood of a conversation in the first electrical audio input signal 301 based on the first electrical audio input signal 301. In this particular embodiment, the conversation detector CD1 is based on an own voice detector configured to detect the presence of the user's voice. The own voice detector may, for example, detect the user's voice based on spectral characteristics or spatial characteristics present in the first electrical audio input signal 301, e.g., that the user's own voice originates for a certain spatial position or direction relative to the first hearing aid HA1. The conversation parameter 304 is a value between 0 and 1, where a value close to 0 indicates the likelihood of the absence of the user's own voice or the likelihood of the absence of a conversation, whereas a value close to 1 indicates the likelihood of the presence of the user's own voice or the likelihood of the presence of a conversation.
The first hearing aid comprises a first wireless link quality detector WLQ1 configured to detect the quality of the wireless link between the first hearing aid HA1 and the second hearing aid HA2, and provide a wireless link quality 305 with a value between 0 and 1. A first wireless link quality 305 close to a value of 1 indicates a stable link between the first hearing aid HA1 and the second hearing aid HA2. A first wireless link quality 305 close to a value of 0 indicates an unstable link between the first hearing aid HA1 and the second hearing aid HA2. The first hearing aid HA1 comprises a first threshold THR1. The first threshold THR1 is a value between 0 and 1 and is set by a hearing aid developer. The first threshold THR1 receives the first wireless link quality 305 and determines whether the first wireless link quality 305 is above or equal to the first threshold THR1. The first threshold THR1 is configured to provide a first controller value 306 of 1 if the first wireless link quality 305 is above or equal to the first threshold THR1. If not, the first threshold THR1 is configured to provide a first controller value 306 of 0.
The first hearing aid HA1 comprises a first output unit OUT1 configured to provide a first audible output signal 305 based on the first processed signal 302. The first output unit OUT1 is a hearing aid receiver (i.e., a hearing aid loudspeaker) for producing sound being audible for the hearing aid user.
The second hearing aid HA2 comprises a second input unit IN2 configured to provide a second electrical audio input signal 401. The second input unit IN2 may comprise a microphone or a plurality of microphones configured to pick-up sound. The microphone may be on the second hearing aid. The second input unit may comprise an analog-to-digital converter (ADC) for sampling the electrical signal provided by the microphone.
The second hearing aid HA2 comprises a second noise reduction system NRS2 comprising a second noise reduction parameter configured to attenuate noise in the second electrical audio input signal 401 and for providing a second processed signal 402 based on the second electrical audio input signal 401. The second electrical audio input signal 401 is represented in the frequency domain (or time-frequency domain) using an analysis filter bank (e.g., based on the discrete Fourier transform or the short-time Fourier transform) but may in some other embodiments be represented in the time-domain. In the frequency domain, the second electrical audio input signal 401 comprises a plurality of frequency band signals. The second noise reduction system NRS2 may comprise a second beamformer BF2 if the second noise reduction system NRS2 receives a plurality of second electrical audio input signals 301, for example, if the second input unit IN2 comprises a plurality of microphones. If the second hearing aid HA2 only comprises one microphone or if only one microphone is enabled or non-defective, the second beamformer BF2 may be bypassed. The second beamformer BF2 may be configured to combine the plurality of second electrical audio input signals 301 and provide a second beamformed signal. The second beamformer BF2 may for example be a delay-and-sum beamformer or a minimum variance distortionless response (MVDR) beamformer. The beamformer coefficients of the second beamformer BF2 may be determined during noise-only time segments where the target speaker (i.e., the conversational partner or the desired speaker) is silent. Noise-only time segments may be determined by a voice activity detector constituting the second noise reduction system NRS2. The second noise reduction system NRS2 comprises a second post-filter PF2. The second post-filter PF2 may be a filter configured to gain or attenuate particular parts of the frequency spectrum of the second beamformed signal or the second electrical audio input signal 301. The second post-filter PF2 comprises a second gain input-output map configured to provide a second gain value of frequency band signal of the second electrical audio input signal 302. The second gain values are applied by multiplication on the frequency band signals of the second beamformed signal or the second electrical audio input signal 301. The second gain input-output map is a function that relates the input to the second gain input-output map to one or more gain values constituting the second post-filter PF2. In this particular embodiment, the input to the second gain input-output map is based on the second beamformed signal. For example, the input to the second gain input-output map is based on a second estimated signal-to-noise ratio by a second signal-to-noise estimator constituting the second noise reduction system NRS2 plus a bias value based on a motion bias and/or a conversation parameter. The bias value constitutes the second noise reduction parameter in this particular embodiment. The second signal-to-ratio estimator is configured to determine the second signal-to-noise ratio based on the second electrical audio input signal 301. However, in other embodiments, the input to the second gain input-output map may for example be based on a noise estimate determined by the second noise reduction system NRS2.
The second hearing aid HA2 comprises a second motion sensor MS2 configured to provide a second motion bias 303 of the second hearing aid HA2. The second motion sensor MS2 is in this particular embodiment an accelerometer, but could be any other sensor that can be configured to provide a measurement of acceleration, or orientation, or movements. The second noise reduction system is configured to receive the second motion bias. The second motion sensor MS2 is configured to measure a second sensor value indicative of acceleration, orientation, or movements. The second motion sensor MS2 is configured to determine a second motion bias 303 based on the second sensor value. The second sensor value may in principle be a three-dimensional value, i.e., one value for each x-, y-, and z-axis. The second motion sensor MS2 is configured to map the second sensor value to a value between -1 and 1 indicative of whether the hearing aid user is likely moving the head (e.g., a second motion bias close to -1) or whether the hearing aid user is likely holding the head still (e.g., a second motion bias close to 1).
The second hearing aid HA2 comprises a second conversation detector CD2 configured to provide a second conversation parameter 304 indicative of the likelihood of a conversation in the second electrical audio input signal 301 based on the second electrical audio input signal 301. In this particular embodiment, the conversation detector CD2 is based on an own voice detector configured to detect the presence of the user's voice. The own voice detector may, for example, detect the user's voice based on spectral characteristics or spatial characteristics present in the second electrical audio input signal 301, e.g., that the user's own voice originates from a certain spatial position or direction relative to the second hearing aid HA2. The conversation parameter 304 is a value between 0 and 1, where a value close to 0 indicates the likelihood of the absence of the user's own voice or the likelihood of the absence of a conversation, whereas a value of close to 1 indicates the likelihood of the presence of the user's own voice or the likelihood of the presence of a conversation.
The second hearing aid comprises a second wireless link quality detector WLQ2 configured to detect the quality of the wireless link between the second hearing aid HA1 and the second hearing aid HA2, and provide a wireless link quality 305 with a value between 0 and 1. A second wireless link quality 305 close to a value of 1 indicates a stable link between the first hearing aid HA1 and the second hearing aid HA2. A second wireless link quality 305 close to a value of 0 indicates an unstable link between the second hearing aid HA1 and the second hearing aid HA2. The second hearing aid HA2 comprises a second threshold THR2. The second threshold THR2 is a value between 0 and 1 and is set by a hearing aid developer. The second threshold THR2 receives the second wireless link quality 305 and determines whether the second wireless link quality 305 is above or equal to the second threshold THR2. The second threshold THR2 is configured to provide a second controller value 306 of 1 if the second wireless link quality 305 is above or equal to the second threshold THR2. If not, the second threshold THR2 is configured to provide a second controller value 306 of 0.
The second hearing aid HA2 comprises a second output unit OUT2 configured to provide a second audible output signal 305 based on the second processed signal 302. The second output unit OUT2 is a hearing aid receiver (i.e., a hearing aid loudspeaker) for producing sound audible for the hearing aid user.
The first hearing aid HA1 is configured to wirelessly transmit the first motion bias 303 and the first conversation parameter 304 to the second hearing aid HA2. The second hearing aid HA2 is configured to wirelessly transmit the second conversation parameter 404 to the first hearing aid HA1.
The first hearing aid comprises a first controller CTR1. The first controller CTR1 is configured to provide the first conversation parameter 304 and the second conversation parameter 404 if the first controller value 306 is a value of 1, i.e., indicative of a stable link between the first hearing aid HA1 and the second hearing aid HA2. The first controller CTR1 is configured to provide the first conversation parameter 304 if the first controller value 306 is a value of 0, i.e., indicative of an unstable link between the first hearing aid HA1 and the second hearing aid HA2.
The first hearing aid HA1 comprises a first maximizer MAX1. The first maximizer MAX1 is configured to provide the first conversation parameter 304 if the first conversation parameter 304 is equal to or greater than the second conversation parameter 404. The first maximizer MAX1 is configured to provide the second conversation parameter 404 if the first conversation parameter 304 is smaller than the second conversation parameter 404. If the first controller value 306 is indicative of an unstable link, the first maximizer MAX1 is configured to provide the first conversation parameter.
The first noise reduction system NRS1 is configured to combine the first or second conversation parameter with the first motion bias and provide a first combined parameter. The first noise reduction parameter is in this particular embodiment the first combined parameter. The combination is based on a multiplication between the first or second conversation parameter and the first motion bias.
The second hearing aid comprises a second controller CTR2. The second controller CTR1 is configured to provide the first conversation parameter 304, the second conversation parameter 404, and the first motion bias 303 if the second controller value 306 is a value of 1, i.e., indicative of a stable link between the first hearing aid HA1 and the second hearing aid HA2. The second controller CTR1 is configured to provide the second conversation parameter 404 and the second motion bias 404 if the second controller value 306 is a value of 0, i.e., indicative of an unstable link between the first hearing aid HA1 and the second hearing aid HA2.
The second hearing aid HA2 comprises a second maximizer MAX2. The second maximizer MAX2 is configured to provide the first conversation parameter 304 if the first conversation parameter 304 is equal to or greater than the second conversation parameter 404. The second maximizer MAX2 is configured to provide the second conversation parameter 404 if the first conversation parameter 304 is smaller than the second conversation parameter 404. If the second controller value is indicative of an unstable link, the second maximizer MAX2 is configured to provide the second conversation parameter.
The second noise reduction system NRS2 is configured to combine the first or second conversation parameter with the first or second motion bias and provide a second combined parameter. The second noise reduction parameter is in this particular embodiment the second combined parameter. The combination is based on a multiplication between the first or second conversation parameter and the first or second motion bias.
FIG. 3 shows an exemplary block diagram of an example method according to the present disclosure. The method for providing a first audible output signal and a second audible output signal comprises wirelessly communicating between a first hearing aid and a second hearing aid in step 501. The method comprises providing, by the first hearing aid comprising a first input unit, a first electrical audio input signal in step 502. The method comprises attenuating, by the first hearing aid comprising a first noise reduction system comprising a first noise reduction parameter, noise in the first electrical audio input signal in step 503. The method comprises providing, first noise reduction system, a first processed signal based on the first electrical audio input signal in step 504. The method comprises providing, by the first hearing aid comprising a first motion sensor, a first motion bias of the first hearing aid in step 505. The method comprises providing, by the first hearing aid comprising a first conversation detector, a first conversation parameter indicative of the likelihood of a conversation in the first electrical audio input signal based on the first electrical audio input signal in step 506. The method comprises providing, by the first hearing aid comprising a first output unit, a first audible output signal based on the first processed signal in step 507. The method comprises providing, by the second hearing aid comprising second input unit, a second electrical audio input signal in step 508. The method comprises attenuating, by the second hearing aid comprising a second noise reduction system comprising a second noise reduction parameter, noise in the second electrical audio input signal in step 509. The method comprises providing, second noise reduction system, a second processed signal based on the second electrical audio input signal in step 510. The method comprises providing, by the second hearing aid comprising a second conversation detector, a second conversation parameter indicative of the likelihood of a conversation in the second electrical audio input signal based on the second electrical audio input signal in step 511. The method comprises providing, by the second hearing aid comprising a second output unit, a second audible output signal based on the second processed signal in step 512. The method comprises determining the first noise reduction parameter based on the first motion bias and the first conversation parameter or second conversation parameter, and determining the second noise reduction parameter based on the first motion bias and the first or second conversation parameter in step 513.
It is intended that the structural features of the devices described above, either in the detailed description and/or in the claims, may be combined with steps of the method, when appropriately substituted by a corresponding process.
As used, the singular forms "a," "an," and "the" are intended to include the plural forms as well (i.e. to have the meaning "at least one"), unless expressly stated otherwise. It will be further understood that the terms "includes," "comprises," "including," and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It will also be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, but an intervening element may also be present, unless expressly stated otherwise. Furthermore, "connected" or "coupled" as used herein may include wirelessly connected or coupled. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. The steps of any disclosed method are not limited to the exact order stated herein, unless expressly stated otherwise.
It should be appreciated that reference throughout this specification to "one embodiment" or "an embodiment" or "an aspect" or features included as "may" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the disclosure. Furthermore, the particular features, structures or characteristics may be combined as suitable in one or more embodiments of the disclosure. The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art.
The claims are not intended to be limited to the aspects shown herein but are to be accorded the full scope consistent with the language of the claims, wherein reference to an element in the singular is not intended to mean "one and only one" unless specifically so stated, but rather "one or more." Unless specifically stated otherwise, the term "some" refers to one or more.

Claims

A hearing aid system comprising:
a first hearing aid (HA1) and a second hearing aid (HA2) configured to wirelessly communicate with one another, the first hearing aid (HA1) comprising:
• a first input unit (IN1) configured to provide a first electrical audio input signal (101);

• a first noise reduction system (NRS1) comprising a first noise reduction parameter configured to attenuate noise in the first electrical audio input signal (101) and for providing a first processed signal (102) based on the first electrical audio input signal (101);

• a first motion sensor (MS1) configured to provide a first motion bias (103) of the first hearing aid (HA1);

• a first conversation detector (CD1) configured to provide a first conversation parameter (104) indicative of the likelihood of a conversation in the first electrical audio input signal based on the first electrical audio input signal (101);

• a first output unit (OUT1) configured to provide a first audible output signal (105) based on the first processed signal (102);

the second hearing aid (HA2) comprising:
• a second input unit (IN2) configured to provide a second electrical audio input signal (201);

• a second noise reduction system (NRS2) comprising a second noise reduction parameter configured to attenuate noise in the second electrical audio input signal (201) and for providing a second processed signal (202) based on the first electrical audio input signal (201);

• a second conversation detector (CD2) configured to provide a second conversation parameter (204) indicative of the likelihood of a conversation in the second electrical audio input signal based on the second electrical audio input signal (201);

• a second output unit (OUT2) configured to provide a second audible output signal (205) based on the second processed signal; and

and wherein the first noise reduction parameter is determined based on the first motion bias (103) and the first conversation parameter (104) or second conversation parameter (204), and the second noise reduction parameter is determined based on the first motion bias (103), and the first conversation parameter (104) or the second conversation parameter (204);
A hearing aid system according to any one of claims 1, wherein the second hearing aid comprises a second motion sensor configured to provide a second motion bias, and wherein the second noise reduction parameter is determined based on the first motion bias and the second motion bias.
A hearing aid system according to any one of claims 1-2, wherein the second hearing aid is configured to determine a wireless signal quality of the wireless communication between the first hearing aid and second hearing aid.
A hearing aid system according to claim 3, wherein the second noise reduction parameter is determined based on:
the first motion bias if the wireless signal quality is equal to or above a threshold; or

the second motion bias if the wireless signal quality is below the threshold.
A hearing aid system according to any one of claims 3-4, wherein the second noise reduction parameter is determined based on:
the first conversation parameter or the second conversation parameter if the wireless signal quality is equal to or above a threshold; or

the second conversation parameter if the wireless signal quality is below the threshold.
A hearing aid system according to any one of claims 4-5, wherein if the wireless signal quality is below the threshold, the first noise reduction parameter is determined based on the first motion bias and the first conversation parameter, and the second noise reduction parameter is determined based on the second motion bias, and the second conversation parameter.
A hearing aid system according to any one of claims 1-4, wherein the first noise reduction parameter and second noise reduction parameter are determined based on:
the first conversation parameter if the first conversation parameter is equal to or greater than the second conversation parameter; or

the second conversation parameter if the second conversation parameter is greater than the first conversation parameter.
A hearing aid system according to any one of claims 1-7, wherein the first noise reduction system comprises a first beamformer, and wherein the second noise reduction system comprises a second beamformer, and wherein the first noise reduction parameter is used to adjust the first beamformer, and wherein the second noise reduction parameter is used to adjust the second beamformer.
A hearing aid system according to any one of claims 1-7, wherein the first noise reduction system comprises a first post-filter, and wherein the second noise reduction system comprises a second post-filter, and wherein the first noise reduction parameter is used to adjust the first post-filter, and wherein the second noise reduction parameter is used to adjust the second post-filter.
A method for providing a first and second audible output signals comprising:
wirelessly communicating between a first hearing aid and a second hearing aid;

providing, by the first hearing aid comprising first input unit, a first electrical audio input signal;

attenuating, by the first hearing aid comprising a first noise reduction system comprising a first noise reduction parameter, noise in the first electrical audio input signal;

providing, first noise reduction system, a first processed signal based on the first electrical audio input signal;

providing, by the first hearing aid comprising a first motion sensor, a first motion bias of the first hearing aid;

providing, by the first hearing aid comprising a first conversation detector, a first conversation parameter indicative of the likelihood of a conversation in the first electrical audio input signal based on the first electrical audio input signal;

providing, by the first hearing aid comprising a first output unit, a first audible output signal based on the first processed signal;

providing, by the second hearing aid comprising second input unit, a second electrical audio input signal;

attenuating, by the second hearing aid comprising a second noise reduction system comprising a second noise reduction parameter, noise in the second electrical audio input signal;

providing, second noise reduction system, a second processed signal based on the second electrical audio input signal;

providing, by the second hearing aid comprising a second conversation detector, a second conversation parameter indicative of the likelihood of a conversation in the second electrical audio input signal based on the second electrical audio input signal;

providing, by the second hearing aid comprising a second output unit, a second audible output signal based on the second processed signal; and

CHARACTERIZED IN THAT determining the first noise reduction parameter based on the first motion bias and the first conversation parameter or second conversation parameter, and determining the second noise reduction parameter based on the first motion bias and the first or second conversation parameter.