A hearing aid system

Abstract

The present application discloses a hearing aid system, comprising a first hearing aid device and a mobile device, wherein each of the devices comprises a transmitting unit and a receiving unit, wherein at least one of the devices comprises: a microphone; a signal processor; a first link quality estimation circuit, configured to determine a phase error of an information packet transmitted from another device and received by a receiving unit and to determine a link quality signal based on the phase error; and at least one of the devices is configured to transmit the link quality signal to the other device, and the other device is configured to determine a transmission power level of the information packet based on the link quality signal; at least one of the devices comprises a second link quality estimation circuit, configured to determine whether one or more information packets are lost and / or determine a plurality of bit errors, and the second link quality estimation circuit is configured to determine a second link quality signal based on the determined number of lost information packets and / or the determined plurality of bit errors.

Description

[0001] This application is a divisional application of Chinese patent application 201811044996.0, filed on September 7, 2018, with the invention name “A hearing aid system”. Technical Field

[0002] The present invention relates to low power wireless communication, in particular to a power controller, including power regulation. The present invention particularly relates to a hearing aid system comprising a first hearing aid device and a mobile device, each device comprising a transmitting unit and a receiving unit for establishing a short range wireless link between the devices. Background Art

[0003] First generation wireless link systems for portable listening devices such as hearing aid devices and mobile devices are usually based on a fixed transmitted power between the devices. For example, at the production stage, the transmitter current is (conservatively) matched to the minimum current with which the system can always achieve internal communication, taking into account component tolerances, different working distances between devices due to variations in head size, placement of the mobile device relative to the hearing aid device, etc. The current overhead in a specific setting represents a waste of power for those devices.

[0004] EP2211579 B1 describes a communication system comprising a first and a second portable communication device, each communication device comprising a transmitting and receiving unit for establishing a wireless link between the devices, wherein at least the first communication device is a portable listening device and comprises a control unit for dynamically adjusting the transmission power of its transmission unit (TX) based on a measure of link quality (LQ) provided by a link quality evaluation unit. The link quality evaluation unit of the receiving device is adapted to determine an appropriate transmission power level for the transmitting device in combination with one or more link quality measures.

[0005] For example, the AGC setting is combined with a CRC check, e.g. such that only AGC settings for error-free frames are saved and used to estimate the link quality, or the AGC setting is combined with a BER metric. Summary of the invention

[0006] It is an object of the present invention to provide a hearing aid system comprising a power controller configured to control power consumption in a short range wireless link.

[0007] The object of the present invention is achieved by a hearing aid system comprising a first hearing aid device and a mobile device, wherein each of these devices comprises a transmitting unit and a receiving unit for establishing a short-range wireless link between the devices. At least one of these devices comprises: a microphone configured to receive an acoustic audio signal, a signal processing unit configured to process an audio signal based on the acoustic audio signal, a first link quality estimator, wherein the first link quality estimator can be configured to determine a phase error of an information packet transmitted from the other device and received by the receiving unit and determine a link quality signal based on the phase error, and wherein at least one of these devices can be configured to transmit the link quality signal to the other device, and the other device can be configured to determine the power level of the transmission of the information packet based on the link quality signal via a power controller included therein.

[0008] At least one of the devices may include a power controller configured to adjust a power level of a transmitted information packet based on a link quality signal transmitted by another device including the first link quality estimator.

[0009] The power controller can adjust the transmit power level between a maximum power level and a minimum power level.

[0010] Another object of the present invention is achieved by a hearing aid system comprising a first hearing aid device and a mobile device, wherein each of these devices comprises a transmitting unit and a receiving unit for establishing a short-range wireless link between the devices, wherein at least one of these devices comprises: a first link quality estimator configured to determine a transmission power level of an information packet transmitted from another device and received by the receiving unit by transmitting a link quality signal via the transmitting unit, wherein the first link quality estimator is configured to determine a phase error of the information packet received by the receiving unit and provide a link quality signal based on the phase error, and wherein the other device is configured to determine the transmission power level of the information packet based on the link quality signal.

[0011] This has the advantage that the power consumption can be adapted to current needs.In an embodiment, the power consumption of the short range wireless link is minimized.

[0012] It is known to use an automatic gain controller or a signal strength controller in a communication system for controlling the power of a short-range wireless link. By using a gain controller and / or a signal strength controller, there is no distinction between whether an increase / decrease in gain or signal strength in a link is caused by noise or by an actual signal in the wireless link.

[0013] The advantage of using phase error detection is that changes in the signal-to-noise ratio can be detected. Thus, it is possible to distinguish whether an increase / decrease in gain or signal strength in the link is caused by noise or by an actual signal in the wireless link.

[0014] If the hearing aid system is in a noisy environment, for example including a monitor screen acting as a noise source, and the mobile device transmits an information packet to the first hearing aid device via a short-range wireless link, the noise emitted by the noise source will interfere with the signal including the information packet. The receiving unit, which in this example is the first hearing aid device, detects via a power controller an increase in the signal strength or transmission gain including the information packet when the noise from the noise source interferes with the transmission. In known solutions, the transmitting unit, which in this example is the mobile device, will reduce the transmission power level of the information packet or increase the transmission power when the power level of the interference, i.e. the noise source, is high enough to override the receiver power (the noise is high enough to destroy the link), however, in the present invention, the transmitting unit will keep the transmission power level constant (i.e. the transmission power level is unchanged) even if the noise starts to interfere with the signal. The receiving unit transmits a link quality signal to the transmitting unit. The transmitting unit controls the transmission power level of the information packet based on the received link quality signal. In this specific example, the power level is increased due to the noise provided by the noise source.

[0015] The first link quality estimator determines the phase error based on phase error detection, phase offset detection, frequency error detection, or based on a modulation scheme of the packet.

[0016] The information packets may be data packets and / or audio packets transmitted by the mobile device or the first hearing aid device.

[0017] The first hearing aid device and the mobile device may comprise an antenna coil, and wherein the short-range wireless link may be an inductive coupling between the first hearing aid device and the mobile device.

[0018] The mobile device may be a second hearing aid device or an auxiliary device such as a smartphone or an intermediate streaming device.

[0019] An advantage of the mobile device being the second hearing aid device is that the adaptation of the power consumption to the current needs in binaural communication between the first and the second hearing aid device is improved.

[0020] In this specification, the term "measure of link quality" is also referred to as "link quality" and abbreviated as "LQ". It should be understood that an increase in link quality means a better and more reliable link, while a decrease in link quality means a worse and less reliable link.

[0021] The power controller may also be configured to dynamically adjust the transmit power of the transmit unit used to transmit the information packet based on the measure of link quality.

[0022] At least one device in the hearing aid system has a local energy source, for example in the form of a battery. These devices may be low power devices comprising an energy source having a limited duration without replacement or recharging (such a limited duration is for example in the order of hours or days, such a duration being limited compared to the expected lifetime of the device). The maximum supply voltage of the energy source may be less than 5V, such as less than 4V, such as less than 3V, such as less than 1.5V. A typical duration of the energy source for the device is less than 2 weeks, such as less than 1 week, such as less than 2 days, such as less than 1 day, such as less than 8 hours.

[0023] In general, the wireless link may be of any type that can be used under power-limited conditions, for example in a portable (usually battery-powered) hearing aid device. In an embodiment, the wireless link is a link based on near-field communication, for example an inductive link based on inductive coupling between an antenna coil of the first hearing aid device and the mobile device. In another example, the wireless link is based on far-field, electromagnetic radiation. In yet another example, the communication via the wireless link is arranged according to a specific modulation scheme, for example an analog modulation scheme like FM (frequency modulation) or AM (amplitude modulation), or a digital modulation scheme like FSK (frequency shift keying), PSK (phase shift keying) or FH-SS (frequency hopping spread spectrum).

[0024] The measure of link quality is extracted in a receiving communication device, for example in a first hearing aid device, based on a signal comprising an information packet received from a transmitting communication device.

[0025] The power controller may be configured to determine a transmit power level of the information packet based on a first threshold and a second threshold.

[0026] The link quality signal may include an estimate of the phase error, wherein the estimate of the phase error may be determined by averaging the phase errors of multiple samples / bits of the packet, and the average phase error per packet is further averaged across several packets using, for example, a low pass filter. The average across several packets is recorded as the link quality phase metric. The link quality signal includes a link quality phase metric expressing the average phase error of several packets.

[0027] If the link quality phase metric is below a first threshold, the power controller is configured to reduce the transmit power level of the information packet, and / or if the link quality phase metric is above a second threshold, the power controller is configured to increase the transmit power level of the information packet. Additionally, if the link quality phase metric is between the two thresholds, the power controller is configured to maintain the transmit power level constant.

[0028] Small changes in the phase error may not affect the audible signal in the information packet in a way that is audible to the user. However, changes in the phase error may lead to unnecessary changes in the transmit power level of the information packet because the first link quality estimator is configured to transmit the link quality signal independently of the level of the phase error, i.e., the level of the link quality phase metric. Thus, applying the teaching that the link quality phase metric must be between the first threshold and the second threshold will prevent a transmitting device, such as the first hearing aid device or the mobile device, from performing unnecessary power adjustments of the transmit power level of the information packet.

[0029] The power controller may also be configured to increase the power level by a first power step based on the link quality signal if the link quality phase metric is above a second threshold, and / or may be configured to decrease the power level by a second power step based on the link quality signal if the link quality phase metric is below a first threshold, wherein the first threshold is less than the second threshold.

[0030] Thus, the value of the first threshold is smaller than the second threshold.

[0031] The first power step size may be larger or smaller than the second power step size, or the first power step size may be equal to the second power step size.

[0032] The first and second power step sizes are increased or decreased based on a ratio between the amount of the link quality phase metric and the time period.

[0033] In an example, only control signals or link quality signals defining the current state of each device, such as settings thereof, are transmitted via the wireless link. In another example, all or part of the audio signal (e.g. certain frequency ranges of the audio signal), possibly including the control signal, is transmitted via the wireless link.

[0034] The measure of the link quality may be extracted in a link quality evaluation unit in a receiving communication device, such as a mobile device, based on a signal received from a transmitting communication device, such as the first hearing aid device.

[0035] The hearing aid system may be adapted to transmit and receive signals according to a digital protocol, wherein the transmitted and received signals may comprise data arranged in packets according to said protocol.

[0036] In an embodiment, the receiving communication device may be adapted to communicate the measure of link quality to a transmitting communication device, such as the first hearing aid device or the mobile device, and the transmitting communication device may be adapted to receive the measure of link quality and adjust the transmission power based on the received measure of link quality.

[0037] Actions to adjust the power level of a transmitter of a transmitting device may be performed after a delay corresponding to the action involved, which delay may depend on the current power level, and / or planned future power levels, and / or the value and / or rate of change of a link quality metric, a rapid rate of change of power level, and / or a sizeable expected change (e.g., more than one power level step), for example resulting in low or no delay in the ensuing adjustment.

[0038] In an embodiment, the link quality metric may be averaged over time. By adjusting the time over which the link quality may be averaged, the reaction speed of the power level adjustment may be affected, with increased averaging time resulting in decreased reaction speed and vice versa.

[0039] The first hearing aid device and / or the mobile device and / or a server connected to the mobile device or the first hearing aid device may comprise a memory for storing the link quality signal and / or the location of a user wearing the hearing aid device and / or the mobile device.

[0040] At least one of these devices, the first hearing aid device and / or the mobile device may be configured to determine a link quality signal based on the location of a user wearing the hearing aid device and / or the mobile device. In this example, the mobile device may communicate with a server having the location of the user of the first hearing aid device. The first hearing aid device, the mobile device, or the server may include a memory unit. The first hearing aid device may be directly or indirectly connected to the server via the mobile device. The memory unit may include a noise map that determines the location of the noise source and the noise field of the noise source. The mobile device or the first hearing aid device may receive status information of the noise source from the server based on the location of the user. The status information includes, for example, whether the noise source is turned on or off, i.e., whether the noise source emits noise. The mobile device, the first hearing aid device, or the server may include a first link quality estimator for determining a link quality signal based on the location of the user and the noise source and the noise field of the corresponding noise source.

[0041] An advantage of detecting the user's position is that the hearing aid system can predict when transmit phase errors are likely to occur due to external noise sources. Thus, a power controller of a transmitting device, such as a mobile device, can increase the transmit power before actual phase errors start to occur.

[0042] At least one of these devices, the first hearing aid device and / or the mobile device may include a second link quality estimator, wherein the second link quality estimator may be configured to determine whether one or more information packets are lost and / or determine a number of bit errors, and the second link quality estimator may be configured to determine a link quality signal based on the determined number of lost information packets and / or the determined number of bit errors.

[0043] At least one of these devices, e.g. the first hearing aid device, may comprise a power controller configured to adjust a transmit power level of the information packet based on a link quality signal transmitted by another device comprising a second link quality estimator or based on a link quality signal transmitted by a second link quality estimator of the device comprising the power controller.

[0044] Detecting the phase error reduces the risk of getting phase errors and / or missing packets when transmitting between the first hearing aid device and the mobile device. By combining the two quality estimators, sudden phase errors and / or missing packets can still be detected and corrected by the power controller of the transmitting device.

[0045] The hearing aid system may combine multiple link quality metrics to determine an appropriate transmit power level for the transmitting means, i.e. the device transmitting the information packet. A combination of the first link quality estimator and the second link quality estimator, i.e. a combination of phase error detection and BER detection, is used alone to determine an appropriate transmit power level.

[0046] The first link quality estimator and the second link quality estimator are each configured to continuously determine a link quality signal.The link quality signal may comprise information about the number of lost packets and / or a determined number of bit errors and / or a determined phase error.

[0047] At least one device may be configured to continuously determine the link quality signal based on the determined number of lost packets (number of lost packets) and / or the determined number of bit errors and / or the determined phase error.

[0048] The first link quality estimator and the second link quality estimator are each configured to continuously determine the link quality signal in parallel or sequentially.

[0049] In a preferred example, the first link quality estimator and the second link quality estimator operate simultaneously.

[0050] The power controller may be configured to adjust the transmit power of the information packet according to the power step size. The power controller may be configured to increase the power level by a first power step size if the link quality phase metric is above a second threshold value; and / or the power controller may be configured to decrease the power level by a second power step size if the link quality phase metric is below the first threshold value, wherein the first threshold value is less than the second threshold value.

[0051] The power controller can also be configured to increase the transmission power level of the information packet by a third power step based on the link quality signal and the second link quality estimator. The third power step is increased or decreased based on the ratio between the number of lost information packets and the time period or the ratio between the number of bit errors and the time period.

[0052] If, for example, the time period between each bit error decreases or the frequency increases, the third power step size must be increased to obtain a faster response to the increasing number of bit errors occurring in the transmission of the information packet.

[0053] If the phase error starts to increase more quickly, the power controller can be configured to increase or decrease the first and second step sizes. Thus, in order to obtain a faster response to the rapid growth of the phase error, the first / second step size must be increased.

[0054] Another object of the present invention is achieved by a method for determining a transmission power level of an information packet between a first hearing aid device and a mobile device, wherein the method comprises:

[0055] - transmitting the information packet from another device to at least one of the devices via the transmitting unit;

[0056] - receiving an information packet via a receiving unit of at least one of the devices;

[0057] - Detecting phase errors of information packets received by the receiving unit;

[0058] -determining a link quality signal based on the phase error;

[0059] - Transmit link quality signal to another device;

[0060] -Determining a transmit power level of information packets in another device based on the link quality signal.

[0061] The first link quality estimator and / or the second link quality estimator may be configured to evaluate the link quality and provide a link quality signal according to a predetermined scheme, for example at regular time intervals, for example ≥ every 100s, such as ≥ every 10s, or such as ≥ every 1s. Alternatively, the moment of evaluating the link quality may be determined dynamically, for example according to the current and / or planned future transmit power level or based on the link quality or power level recorded for previous time intervals, such as the last hour or the last 10 minutes or the last minute or the last 10s or the last 1s or less. The time between the evaluation of the link quality and the possible adjustment of the transmit power level may decrease when the transmit power level increases.

[0062] The link quality may be continuously monitored. The transmit power level may be continuously adjusted. The transmit power level is adjusted according to a predetermined scheme (if changes are necessary), for example with a delay of 1 s or 5 s or 10 s or 20 s or according to the current link quality or the rate of change of the link quality (a large rate of change of the link quality causes a rapid change of the transmit power level).

[0063] The power controller is configured to boost its own transmitter power when several packets are lost. If the first hearing aid device has lost several packets from the other device in a row, the most likely scenario is that the other side cannot receive the link quality signal from the first hearing aid device, therefore, the power controller of the first hearing aid device is configured to increase the transmission power of the link quality signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Various aspects of the present invention will be best understood from the detailed description below in conjunction with the accompanying drawings. For clarity, the drawings are schematic and simplified, and only the details necessary for understanding the present invention are given, while other details are omitted. In all drawings, the same reference numerals are used for the same or corresponding parts. The various features of each aspect may be combined with any or all features of the other aspects. These and other aspects, features and / or technical effects will be apparent from and illustrated in conjunction with the following figures, in which:

[0065] Figure 1 A hearing aid system is shown.

[0066] Figure 2 A hearing aid system comprising a second link quality estimator is shown.

[0067] Figure 3a and 3b Measurements of a hearing aid system are shown.

[0068] Figure 4a and 4b Measurements of a hearing aid system comprising a second link quality estimator are shown.

[0069] Figure 5 A first threshold and a second threshold are shown.

[0070] Figure 6 A hearing aid system is shown.

[0071] Figure 7 A hearing aid system is shown.

[0072] Figure 8 An example of a hearing aid system is shown. DETAILED DESCRIPTION

[0073] The detailed description presented below in conjunction with the accompanying drawings serves as a description of a variety of different configurations. The detailed description includes specific details for providing a thorough understanding of a number of different concepts. However, it is apparent to those skilled in the art that these concepts can be implemented without these specific details. Several aspects of the apparatus and method are described by a number of different blocks, functional units, modules, components, circuits, steps, processes, algorithms, etc. (collectively referred to as "elements"). Depending on the specific application, design limitations or other reasons, these elements can be implemented using electronic hardware, computer programs or any combination thereof.

[0074] The hearing aid device may include a hearing aid adapted to improve or enhance the hearing ability 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.

[0075] The hearing aid device is adapted to be worn in any known manner. This may include i) arranging a unit of the hearing aid device having a tube for guiding airborne acoustic signals and / or a receiver / speaker arranged close to or in the ear canal behind the ear, such as in a behind-the-ear hearing aid or an in-the-ear receiver-type hearing aid; and / or ii) arranging the hearing device in its entirety or in part in the auricle and / or in the ear canal of the user, such as in an in-the-ear hearing aid or an in-the-canal / deep-in-the-canal hearing aid; or iii) arranging the unit of the hearing device to be connected to a fixed structure implanted in the skull, such as in a bone-anchored hearing aid or a cochlear implant; or iv) arranging the unit of the hearing device as a fully or partially implanted unit, such as in a bone-anchored hearing aid or a cochlear implant.

[0076] The hearing aid device may be part of a "hearing aid system" comprising one or two hearing devices disclosed in the present specification or a "binaural hearing system" comprising two hearing devices (wherein these devices are adapted to provide audio signals to both ears of a user in a cooperative manner). The hearing aid system or binaural hearing system may also include a mobile device that communicates with at least one hearing aid device, the mobile device affecting the operation of the hearing aid device and / or benefiting from the operation of the hearing aid device. A wired or wireless communication link is established between at least one hearing aid device and the mobile device, enabling information (e.g., control and status signals, possibly audio signals) to be exchanged between at least one hearing aid device and the mobile device. The mobile device may include at least one of a remote control, a remote microphone, an audio gateway device, a mobile phone, a public address system, a car audio system, or a music player, or a combination thereof. The audio gateway is adapted to receive a large number of audio signals, such as from an entertainment device like a TV or a music player, a telephone device like a mobile phone, or a computer, a PC. The audio gateway is also adapted to select and / or combine a suitable one of the received audio signals (or a combination of signals) for transmission to at least one hearing aid device. The remote control may be adapted to control the functions and operations of at least one hearing aid device. The functionality of the remote control may be implemented in a smartphone or other electronic device, which may run an application that controls the functions of at least one hearing aid device.

[0077] Generally, a hearing aid device comprises i) an input unit such as a microphone for receiving acoustic signals from the user's surroundings and providing a corresponding input audio signal, and / or ii) a receiving unit for electronically receiving the input audio signal. The hearing aid device also comprises a signal processing unit for processing the input audio signal and an output unit for providing an audible signal to the user based on the processed audio signal.

[0078] The input unit may include multiple input microphones, for example for providing direction-dependent audio signal processing. Such a directional microphone system is suitable for enhancing a target acoustic source from a large number of acoustic sources in a user's environment. In one aspect, the directional system is suitable for detecting (e.g., adaptively detecting) from which direction a particular portion of the microphone signal originates. This can be achieved using conventionally known methods. The signal processing unit may include an amplifier, which is suitable for applying a frequency-dependent gain to the input audio signal. The signal processing unit may also be suitable for providing other related functions such as compression, noise reduction, etc. The output unit may include an output transducer such as a speaker / receiver for providing air-borne acoustic signals to the skull transcutaneously or percutaneously, or a vibrator for providing structure-borne or liquid-borne acoustic signals. In some hearing aid devices, the output unit may include one or more output electrodes such as in a cochlear implant for providing electrical signals.

[0079] It should be appreciated that reference to "an embodiment" or "embodiment" or "aspect" or features that "may" be included in this specification means that the specific features, structures or characteristics described in conjunction with the embodiment are included in at least one embodiment of the present invention. In addition, the specific features, structures or characteristics may be appropriately combined in one or more embodiments of the present invention. The foregoing description is provided to enable those skilled in the art to implement the various aspects described herein. Various modifications will be apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects.

[0080] The claims are not limited to the various aspects shown herein, but rather have the full scope consistent with the claim language wherein, unless expressly stated otherwise, elements referred to in the singular do not mean "one and only one" but rather "one or more." Unless expressly stated otherwise, the term "some" means one or more.

[0081] Therefore, the scope of the present invention should be judged based on the following claims.

[0082] Figure 1 A hearing aid system 1 is shown. The hearing aid system 1 comprises a first hearing aid device 2 and a mobile device 3, wherein each of these devices (2, 3) comprises a transmitting unit 9 and a receiving unit 9 for establishing a short-range wireless link 10 between the devices (2, 3). At least one of these devices 2 comprises: a microphone 5 configured to receive an acoustic audio signal, a signal processing unit 4 configured to process an audio signal based on the acoustic audio signal, a first link quality estimator 8, wherein the first link quality estimator 8 can be configured to determine a phase error of an information packet transmitted from the other device 3 and received by the receiving unit 9 and determine a link quality signal based on the phase error, and wherein at least one of these devices 2 can be configured to transmit the link quality signal to the other device 3, and the other device 3 can be configured to determine a power level of transmission of the information packet based on the link quality signal via a power controller 7 comprised therein.

[0083] In this specific example, the first hearing aid device 2 may optionally comprise a power controller 7 configured to adjust the power level of the transmitted information packets based on a link quality signal transmitted by the further device 3 which optionally comprises a first link quality estimator 8 .

[0084] Optionally, these devices include a loudspeaker 6 .

[0085] Figure 2A hearing aid system comprising a second link quality estimator 13 is shown. At least one of the devices (2, 3), the first hearing aid device 2 and / or the mobile device 3 may comprise a second link quality estimator 13, wherein the second link quality estimator 13 is configured to determine a link quality signal based on determining whether one or more information packets are lost and / or determining a number of bit errors (a number of bit errors). The second link quality estimator is configured to determine a link quality signal based on the determined number of lost information packets and / or the determined number of bit errors.

[0086] The second link quality estimator 13 may comprise bit error detection and / or detection of lost packets, CRC error detection or packet loss.

[0087] In this specific example, the first hearing aid device 2 comprises a second link quality estimator 13. The first hearing aid device 2 is then configured to continuously determine a link quality signal via the second link quality estimator 13 based on the determined number of lost packets and / or number of bit errors, and via the first link quality estimator 8 the first hearing aid device 2 is configured to continuously determine a link quality signal based on the determined phase error.

[0088] Figure 3a and 3b A measurement of a hearing aid system 1 is shown, which illustrates the functionality of the first link quality estimator 8 together with the power controller 7 .

[0089] The measurement is provided for the transmission of a packet comprising a plurality of samples, and the link quality estimator 8 is configured to estimate the phase error for each received sample / bit and average the phase error across the entire packet. The average phase error for each received sample is recorded as the link quality phase metric. At 20, the link quality phase metric is less than a first threshold value th1, and at 21, the link quality phase metric is greater than a second threshold value th2.

[0090] The power controller adjusts the transmit power level 23 according to the link quality phase metric estimated by the first link quality estimator 8. At 24, the power controller 7 reduces the power level 23 because the link quality phase metric is below the first threshold th1. The power controller 7 is configured not to reduce the power level 23 below a predetermined minimum value. The power controller 7 may reduce the power level 23 by a second power step size Δs2.

[0091] At 25, the power controller 7 of the transmitting device (2 or 3) increases the transmit power level 23 because the link quality phase metric is above a second threshold value th2, i.e. the phase error is at a critical amount to corrupt, for example, the audio in the information packet. The power controller 7 increases the power level 23 by a first power step size Δs1. In this specific example, the first power step size is larger than the second power step size due to the CRC error.

[0092] The power controller 7 is configured not to increase the power level 23 above a predetermined maximum value.

[0093] Figure 4a and 4b A measurement of a hearing aid system 1 is shown, which illustrates the functionality of the second link quality estimator 13 together with the power controller 7 .

[0094] At 20, the link quality phase metric is less than a first threshold value th1; and at 21, the link quality phase metric is greater than a second threshold value th2. It can be seen that the power controller 7 reduces the power level corresponding to the link quality phase metric being less than the first threshold value th1, and the power controller 7 increases the power level due to the link quality phase metric being greater than the second threshold value. At 27, the transmission experiences a bit error or a lost packet, and the power controller 7 responds by increasing the power level 23 by a third power step Δs3, which is greater than the second power step Δs2 used to reduce the power level 23.

[0095] At 27, a number of lost packets or bit errors have occurred and the power controller 7 significantly increases the transmit power level 23 for a short period of time. The loss of packets ceases and the power controller 7 reduces the power level 23 to a minimum power level.

[0096] Figure 5 A first threshold th1 and a second threshold are shown and how the power controller 7 changes the transmit power level 23 in response to the link quality phase metric being between the two thresholds (th1, th2) or below the first threshold or above the second threshold. Between time 0 and t1, the change in the link quality phase metric can be seen. Between 0 and t1, the power controller does not change the power level because the transmit power is already at a minimum level. At time t1, it can be seen that the power controller increases the power because the link quality phase metric has increased above the second threshold th2. At time t2, the power controller 7 increases the power more because the first increase in power at time t1 did not reduce the amount of the link quality phase metric. At time t3, the power controller 3 increases the transmit power again, and at time t4, the link quality phase metric is now between the two thresholds (th1, th2), and the power controller 7 keeps the transmit power constant. At time t5, the link quality phase metric has dropped below the first threshold th1 and the power controller reduces the transmit power.

[0097] Figure 6A hearing aid system 1 is shown, in which at least one of the devices (2, 3), i.e. the first hearing aid device 2 and / or the mobile device 3, comprises in this example a first link quality estimator 8 and / or a second link quality estimator 13. In this specific example, both estimators receive received information packets from a receiving unit 9. The first link quality estimator 8 estimates the phase error for each received sample / bit of the information packet and averages the estimated phase error for each sample / bit across the entire packet. Thereafter, the average phase error per information packet is further averaged between several information packets using a low pass filter 30. This further averaged phase error is recorded as a link quality phase metric 35. Thereafter, the link quality phase metric 35 is checked against two thresholds (th1, th2). If the metric 35 is below the first threshold th1, the link quality is not necessarily too high, and therefore the power controller transmits a link quality signal (31, 9) to the mobile device, and the power controller 7 of the mobile device is configured to reduce its transmit power 23. If the metric 35 is above the second threshold th2, the link quality is too low, and the power controller will therefore command (32, 9) the mobile device to increase its power by transmitting a link quality signal. The first hearing aid device 2 may also be configured to command itself to increase the power of the transmitting unit 9 in the first hearing aid device 2, in order to enable the other device 3 to receive the link quality signal.

[0098] The threshold value can be dynamically changed according to the bit error rate range required for transmission between the two devices. The required bit error rate range can be 10 -5 and 10 -7 As an alternative, the threshold value may be predetermined according to a desired bit error rate range.

[0099] The power controller 7 of the first hearing aid device 2 or the mobile device 3 may also be informed about the CRC 33 errors or packet losses 34 via the second link quality estimator 13. The power controller 7 will then request the other device 3 to increase its transmit power 23. If the first hearing aid device 2 is not able to communicate with the other device 3, the power controller 7 of the device 2 is configured to increase the power of the transmit unit 9 of the first hearing aid device 2 if the first hearing aid device does not suffer any impact on the transmit link quality when transmitting the one or more link quality signals.

[0100] The mobile device 3 may be a transmitting or receiving device for information packets, and the functional component of the first hearing aid device may be a transmitting or receiving device for information packets.

[0101] Figure 7At least one of the devices (2, 3) of the hearing aid system 1 is shown to include a memory for storing a link quality signal and / or a position of a user wearing the hearing aid device and / or the mobile device. The hearing aid system 1 may include a server, which may be connected to the mobile device or the first hearing aid device via a wireless link. The server may include a memory 12. In addition, at least one of the devices may include an antenna coil 11 configured to transmit and / or receive wirelessly. The antenna coil 11 may be configured to communicate over a short range and / or over a long range via a wireless link.

[0102] Figure 8 It is shown that at least one of the devices (a first hearing aid device 2 and / or a mobile device 3) is configured to determine a link quality signal based on the location of a user (40A, 40B) wearing the hearing aid device 2 and / or the mobile device 3. In this example, one of the users 40A wears a hearing aid system 1, wherein the mobile device 3 is a second hearing aid device configured to communicate with a server 41, and another user 40B wears another hearing aid system 1, wherein the mobile device 3 is a smartphone configured to communicate with the server 41. Both hearing aid systems 1 of the two users (40A, 40B) communicate with a server having the location 43 of the respective user (40A, 40B). The first hearing aid device 2, the mobile device 3 and / or the server 41 may include a memory unit 12. The memory unit 12 may include a noise map, which defines the location of noise sources (42A, 42B) and the corresponding noise fields (44A, 44B). Both hearing aid systems receive status information of the noise sources from the server 41 based on the location 43 of the respective user (40A, 40B). The state information includes, for example, whether the noise source (42A, 42B) is turned on or off, i.e., whether the noise source (42A, 42B) emits noise. A first respective link quality estimator of the respective hearing aid system determines a link quality signal based on a position of the respective user (40A, 40B) relative to the noise source (42A, 42B) and a respective noise field (44A, 44B).

[0103] In this specific example, one of the users 40A walks through the noise field 44A of one of the noise sources 42A and it can be clearly seen that the phase error 21 of the transmission of the information packets, expressed as a link quality phase measure, increases above the second threshold th2. Thereafter, the power controller 7 of the hearing aid system 1 of the user 40A increases the transmission power 23 to improve the link quality of the wireless link between the two devices (2, 3) of the hearing aid system 1. Thereafter, due to the increase in power 23, the phase error in the transmission of the information packets decreases to a level between the first threshold th1 and the second threshold th2. The power controller 7 does not change the power 23. The phase error 20 decreases below the first threshold th1 and the power controller 7 starts to decrease the power 23 by a certain power step, namely the first power step or the second power step, to reduce the power consumption of the hearing aid system and thereby obtain a long life of the batteries in the first hearing aid device 2 and the second hearing aid device 3.

[0104] The user continues his walking, and as the user 40A walks toward another noise source 42B, the power controller 7 reduces the power 23 more until the user 40A reaches the noise field 44B of the other noise source 42B. The power controller 7 immediately compensates for the poor link quality by increasing the power 23. When the user 40A is outside the noise field 44B of the other noise source 42B, the power 23 is reduced again.

Claims

1. A hearing aid system, comprising a first hearing aid device and a mobile device, wherein each of the first hearing aid device and the mobile device comprises a transmitting unit and a receiving unit for establishing a short-range wireless link between the devices, wherein at least one of the first hearing aid device and the mobile device comprises: - a microphone configured to receive an acoustic audio signal; - a signal processor configured to process an audio signal based on the acoustic audio signal; - a first link quality estimation circuit configured to determine a phase error of an information packet transmitted from another device and received by a receiving unit and to determine a first link quality signal based on the phase error; wherein the phase error is determined by averaging the phase errors of a plurality of samples / bits of the information packet, and the average phase error per information packet is further averaged between several information packets; and wherein the device including the first link quality estimation circuit is configured to transmit the first link quality signal to another device; wherein the first hearing aid device and / or the mobile device comprises a second link quality estimation circuit, wherein the second link quality estimation circuit is configured to determine whether one or more information packets are lost and / or to determine a number of bit errors, and the second link quality estimation circuit is configured to determine a second link quality signal based on the determined number of lost information packets and / or the determined number of bit errors; The first hearing aid device and / or the mobile device is configured to determine the transmission power level of the information packet of the mobile device or the first hearing aid device between a maximum power level and a minimum power level based on the first link quality signal and / or the second link quality signal via a power controller included therein. 2 . The hearing aid system according to claim 1 , wherein at least one of the first hearing aid device and the mobile device is configured to continuously determine the first link quality signal and the second link quality signal.

3. The hearing aid system according to claim 1, wherein the second link quality estimation circuit is based on bit error detection and / or detection of lost packets, cyclic redundancy check error detection or packet loss.

4. The hearing aid system of claim 1, wherein the power controller is configured to increase the transmit power level of the information packet by a third power step size based on the first link quality signal and the second link quality signal. 5 . The hearing aid system according to claim 4 , wherein the third power step size is increased or decreased based on a ratio between a number of lost packets and a time period or a ratio between a number of bit errors and the time period.

6. The hearing aid system of claim 1, wherein the first link quality estimation circuit determines the phase error based on phase error detection, phase offset detection, frequency error detection, or a modulation scheme based on the packet.

7. The hearing aid system according to claim 1, wherein the information packet is a data packet and / or an audio packet transmitted by the mobile device or the first hearing aid device.

8. The hearing aid system of claim 1, wherein the mobile device is a second hearing aid device or an auxiliary device.

9. The hearing aid system according to claim 1, wherein the first hearing aid device and / or the mobile device comprises a memory for storing the first and / or second link quality signals and / or a location of a user wearing the hearing aid device and / or the mobile device.

10. The hearing aid system of claim 1, wherein: The average phase error per packet is further averaged among several packets using a low pass filter.

11. A hearing aid system according to claim 6 or 10, wherein the determined phase error is recorded as a link quality phase metric, and wherein the power controller is configured to determine the transmission power level of the information packet to be constant when the link quality phase metric is between a first threshold and a second threshold, and / or the power controller is configured to increase the transmission power level by a first power step based on a first link quality signal when the link quality phase metric is above the second threshold, and / or the power controller is configured to decrease the transmission power level by a second power step based on the first link quality signal when the link quality phase metric is below the first threshold, wherein the first threshold is less than the second threshold.

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