Method for estimating state of charge of hearing aid

Abstract

The present application discloses a method for estimating a state of charge of a hearing aid, the method comprising determining a value of the state of charge based on a weighted combination of a first state of charge estimate determined using a voltage model and a second state of charge estimate determined by tracking a charge flow or an energy flow of a battery; wherein the combination of the first weight of the first state of charge estimation value and the second weight of the second state of charge estimation value corresponds to the maximum weight; wherein determining the first state of charge estimate comprises: determining whether the battery is in a charged state or a discharged state, determining the first state of charge estimate using a voltage model and a battery voltage while the battery is in the discharged state, and determining the second state of charge estimate using the voltage model and the battery voltage while the battery is in the charged state. A first state of charge estimate is determined using a voltage model and a modeled voltage potential difference between charge and discharge.

Description

Technical Field

[0001] The present application relates to the field of hearing aids, and in particular to a method for estimating the state of charge of a hearing aid. Background Art

[0002] The state of charge is used to determine the battery level of the hearing aid and is therefore used to provide the user with the hearing aid's battery level.

[0003] It is known to determine the state of charge of a hearing aid during a discharge state of the hearing aid using a voltage model that can be predetermined and / or updated.

[0004] However, using the aforementioned voltage model during the charging state of the hearing aid or when changing from the charging state to the discharging state or vice versa results in an inaccurate estimate of the state of charge.

[0005] Therefore, a more accurate solution for determining the state of charge of a hearing aid is needed. Summary of the Invention

[0006] In one aspect of the present application, a method for estimating the state of charge of a hearing aid comprising a rechargeable battery is provided.

[0007] The method includes determining a state of charge value based on a weighted combination of a first state of charge estimate determined using a voltage model and a second state of charge estimate determined by tracking charge flow or energy flow of the battery.

[0008] A combination of the first weight of the first estimated value and the second weight of the second estimated value corresponds to a maximum weight.

[0009] Determination of the first state of charge estimate includes determining whether the battery is in a charging state or a discharging state.

[0010] Determining the first state of charge estimate includes determining the first state of charge estimate using a voltage model and a battery voltage when the battery is in a discharged state. Determining the first state of charge estimate includes determining the first state of charge estimate using a voltage model and a modeled voltage potential difference between charging and discharging when the battery is in a charged state.

[0011] Tracking the charge flow or energy flow of the battery enables improved accuracy of the state of charge estimation, particularly in certain situations, such as when transitioning from a charged state to a discharged state of the battery or vice versa.

[0012] The weighted combination thus enables accurate determination of the state of charge during all phases of battery operation.

[0013] Determining the first SOC estimate based on the voltage model may enable a more improved (eg, accurate) SOC estimate.

[0014] Specifically, by using a voltage model (e.g., a discharge curve) and the battery voltage to determine a first state of charge estimate when the battery is in a discharge phase, and using a voltage model and a modeled voltage potential difference between charging and discharging to determine a first state of charge estimate when the battery is in a charge phase, state of charge estimation can be significantly improved. In other words, the use of a voltage model and a model that converts charging and discharging enables improved state of charge estimation.

[0015] Implementations of the present invention advantageously provide inherent consistency between charge predictions and discharge predictions of the first state of charge estimate by basing the determination of the first estimate on a voltage model (eg, a learned curve).

[0016] In an example, the method further includes:

[0017] - determining a first state of charge estimate using the voltage model; and / or

[0018] - Determining a second state of charge estimate by tracking charge flow or energy flow through the battery.

[0019] In the example, the voltage potential difference is modeled as the voltage increase due to the charging current flowing through the resistor, and an additional offset to account for the redistribution effects that occur after charging.

[0020] In an example, the first state of charge estimate is determined using the following formula:

[0021]

[0022] in:

[0023] -SoCV is the first state of charge estimate

[0024] -f_learn is the voltage model

[0025] -Vbat is the battery voltage

[0026] -i_charge is the charging current flowing into the battery

[0027] -R_charge is the modeled charging resistance

[0028] -Alpha is a predetermined value

[0029] -V_relax is another predetermined value that models an additional offset.

[0030] The above formula can be regarded as a model for converting charge and discharge.

[0031] Implementations of the present invention reduce memory usage by determining the state-of-charge estimate in a manner that requires no curve to be stored in memory. Furthermore, system complexity can be reduced, as learning a charging curve can be challenging due to its dependence on parameters such as temperature and / or starting conditions. By basing the determination of the first estimate on a learned curve (e.g., based on a voltage model), inherent consistency between charge predictions and discharge predictions for the first state-of-charge estimate can be provided.

[0032] Alpha can depend on the battery voltage, with the value of Alpha generally being higher at very low voltages:

[0033]

[0034] Therefore, Alpha provides the V_relax value to account for the ability of the redistribution magnitude to vary at different voltage levels.

[0035] In a simple implementation, Alpha may also be set to 1, thereby ignoring variations and providing a rougher approximation.

[0036] V_relax is typically a constant and corresponds to the battery voltage drop when the charging current applied to the battery is no longer applied.

[0037] In an example, the second state of charge estimate is determined using one of the following formulas:

[0038] SoCC(t)=SoC(0)+∫0 t i_batdt

[0039] or

[0040] SoCC(t)=SoC(0)+∫0 t i_bat*Vbatdt

[0041] in:

[0042] -SoCC is the second state of charge estimate

[0043] - SoC(0) is the value of the state of charge after changing from the charging state to the discharging state or from the discharging state to the charging state

[0044] -i_bat is the battery current

[0045] -t is the time since the state changed

[0046] -Vbat is the battery voltage.

[0047] The battery current can be determined using the following formula:

[0048]

[0049] in:

[0050] -i_bat is the battery current

[0051] -i_charge is the charging current flowing into the battery during charging

[0052] -i_discharge is the discharge current that flows from the battery during discharge.

[0053] In an example, when the end condition is met, the second weight decreases toward a minimum weight and / or the first weight increases toward a maximum weight.

[0054] In an example, when the state change condition is satisfied but the end condition is not satisfied, the second weight is set to be substantially equal to the maximum weight and / or the first weight is set to be substantially equal to the minimum weight.

[0055] In another example, the method further includes, when the state change condition is satisfied but the end condition is not satisfied:

[0056] - Determine if the battery is fully charged;

[0057] - if the battery is fully charged, setting the second weight to be substantially equal to the maximum weight; and

[0058] - If the battery is not fully charged, setting the first weight to be substantially equal to the maximum weight.

[0059] In an example, when the state change condition is not satisfied and the end condition is not satisfied, the second weight continues to decrease and / or the first weight continues to increase.

[0060] In another aspect of the present application, another method for estimating the state of charge of a hearing aid comprising a rechargeable battery is provided.

[0061] The method may include determining a state of charge value based on a first state of charge estimate determined using a voltage model.

[0062] Determining the first state of charge estimate may include:

[0063] - Determine whether the battery is in a charging or discharging state;

[0064] - when the battery is in a discharged state, determining a first state of charge estimate using the voltage model and the battery voltage;

[0065] -When the battery is in a charging state, a voltage model is used and the voltage potential difference between charging and discharging is modeled.

[0066] In another aspect of the present application, a hearing aid is provided. The hearing aid comprises:

[0067] - an input unit configured to receive an acoustic signal and convert the acoustic signal into an input signal;

[0068] - a signal processor configured to process an input signal having a hearing loss profile of a user;

[0069] - an output unit configured to transmit the processed signal having the hearing loss profile into an ear of the user; and

[0070] -Rechargeable battery.

[0071] Furthermore, the signal processor is configured to perform one of the methods described above, described in detail in the “Detailed Description of Embodiments”, and defined in the claims.

[0072] The hearing aid may be adapted to provide frequency dependent gain and / or level dependent compression and / or frequency transposition of one or more frequency ranges to one or more other frequency ranges (with or without frequency compression) to compensate for a hearing impairment of a user. The hearing aid comprises a signal processor for enhancing an input signal and providing a processed signal.

[0073] The hearing aid comprises an output unit for providing a stimulus perceived by the user as an acoustic signal based on the processed signal. The output unit may comprise a vibrator of a bone conduction 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 a mechanical vibration of the skull to the user (e.g. in a bone attached or bone anchored hearing aid). The output unit may (in addition or as an alternative) comprise a (e.g. wireless) transmitter for transmitting the sound picked up by the hearing aid (e.g. via a network, e.g. in telephone operating mode, or in a headset configuration) to another device, such as a remote communication partner.

[0074] The hearing aid includes an input unit for providing an electrical input signal representing sound. The input unit may include an input transducer, such as a microphone, for converting the input sound into the electrical input signal. The input unit may include a wireless receiver for receiving a wireless signal including or representing sound and providing the electrical input signal representing the sound.

[0075] The wireless receiver and / or transmitter may be configured to receive and / or transmit electromagnetic signals in the radio frequency range (3 kHz to 300 GHz), for example. The wireless receiver and / or transmitter may be configured to receive and / or transmit electromagnetic signals in the optical frequency range (e.g., infrared light 300 GHz to 430 THz or visible light such as 430 THz to 770 THz), for example.

[0076] A hearing aid may include a directional microphone system adapted to spatially filter ambient sound to enhance a target sound source among multiple sound sources in the local environment of a user wearing the hearing aid. The directional system may be adapted to detect (e.g., adaptively detect) the direction from which a particular portion of the microphone signal originates. This can be achieved in a variety of different ways, such as those described in the prior art. In hearing aids, microphone array beamformers are commonly used to spatially attenuate background noise sources. The beamformer may include a linearly constrained minimum variance (LCMV) beamformer. Many beamformer variants are available in the literature. Minimum variance distortionless response (MVDR) beamformers are widely used in microphone array signal processing. Ideally, an MVDR beamformer leaves the signal from the target direction (also known as the line-of-sight direction) unchanged while maximally attenuating sound signals from other directions. The generalized sidelobe canceler (GSC) structure is an equivalent representation of the MVDR beamformer, offering computational and digital representation advantages over a direct implementation of the original form.

[0077] Most sound signal sources (except the user's own voice) are relatively small compared to the size of the hearing aid, such as the distance d between the two microphones of a directional system. mic Located away from the user. The typical microphone distance in a hearing aid is on the order of 10 mm. The minimum distance from the user's sound source of interest (e.g., the sound from the user's mouth or the sound from the audio transmission device) is 0.1 m (>10 d mic ) level. For such a minimum distance, the hearing aid (microphone) will be in the acoustic near field of the sound source and the level difference of the sound signal incident on the respective microphones may be significant. The typical distance of the communication partner is greater than 1m (>100d mic The hearing aid (microphone) will be in the acoustic far field of the sound source, and the level difference of the sound signals incident on the corresponding microphones will not be obvious. The arrival time difference of the sound incident in the direction of the microphone axis (for example, in front of or behind a normal hearing aid) is ΔT = d mic / v sound =0.01 / 343[s]=29μs, where v sound The speed of sound in air at 20°C (343 m / s).

[0078] The hearing aid may include an antenna and transceiver circuitry that enables a wireless link to an entertainment device (e.g., a television), a communication device (e.g., a telephone), a wireless microphone, a separate (external) processing device, or another hearing aid. The hearing aid may thus be configured to wirelessly receive a direct electrical input signal from another device. Similarly, the hearing aid may be configured to wirelessly transmit a direct electrical output signal to another device. The direct electrical input or output signal may represent or include an audio signal and / or a control signal and / or an information signal.

[0079] In general, the wireless link established by the antenna and transceiver circuitry of the hearing aid may be of any type. The wireless link may be a link based on near field communication, for example an inductive link based on inductive coupling between antenna coils of a transmitter part and a receiver part. The wireless link may be based on far-field electromagnetic radiation. Preferably, the frequency used to establish the communication link between the hearing aid and the other device is below 70 GHz, for example in the range from 50 MHz to 70 GHz, for example above 300 MHz, for example in the ISM range above 300 MHz, for example 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 are defined, for example, by the International Telecommunication Union ITU). The wireless link may be based on standardized or proprietary technologies. The wireless link may be based on Bluetooth technology (for example Bluetooth Low Energy technology, for example LE Audio) or Ultra-Wideband (UWB) technology.

[0080] The hearing aid is a portable (ie, wearable) device and includes a rechargeable battery. The hearing aid may also include a battery circuit including a current accumulator (also known as a coulomb counter or fuel gauge).

[0081] The hearing aid may for example be a low-weight, easily wearable device, for example having a total weight of less than 100 g, such as less than 20 g, for example less than 5 g.

[0082] A hearing aid may include a "forward" (or "signal") path between the input and output of the hearing aid for processing audio signals. A signal processor may be located in this forward path. The signal processor may be adapted to provide frequency-dependent gain according to the specific needs of the user (e.g., hearing loss). The hearing aid may include an "analysis" path having functional components for analyzing signals and / or controlling processing of the forward path. Some or all of the signal processing in the analysis path and / or the forward path may be performed in the frequency domain, in which case the hearing aid includes appropriate analysis and synthesis filter banks. Some or all of the signal processing in the analysis path and / or the forward path may be performed in the time domain.

[0083] The analog electrical signal representing the acoustic signal can be converted into a digital audio signal in an analog-to-digital (AD) conversion process, where the analog signal is sampled at a predetermined frequency or sampling rate f. s Sampling, f s For example, in the range from 8 kHz to 48 kHz (adapted to the specific needs of the application) at discrete time points t n (or n) provides digital samples x n (or x[n]), each audio sample is passed through a predetermined N b The bit represents the sound signal at t n The value when N bFor example, in the range from 1 to 48 bits, such as 24 bits. Each audio sample thus uses N b bit quantization (resulting in 2 Nb different possible values). A digital sample x has a 1 / f s The length of time, such as 50μs, for f s = 20kHz. Multiple audio samples can be arranged in time frames. A time frame can include 64 or 128 audio data samples. Other frame lengths can be used depending on the actual application.

[0084] The hearing aid may include an analog-to-digital (AD) converter to digitize an analog input (e.g., from an input transducer such as a microphone) at a predetermined sampling rate, such as 20 kHz. The hearing aid may also include a digital-to-analog (DA) converter to convert the digital signal into an analog output signal, such as for presentation to the user via an output transducer.

[0085] The hearing aid, such as the input unit and / or the antenna and the transceiver circuit, may comprise a transform unit for converting a time domain signal into a signal in a transform domain (e.g. the frequency domain or the Laplace domain, a Z transform, a wavelet transform, etc.). The transform unit may be constituted by or include a time-frequency (TF) transform unit for providing a time-frequency representation of the input signal. The time-frequency representation may comprise an array or mapping of corresponding complex or real values of the signal in question in a specific time and frequency range. The TF transform unit may comprise a filter bank for filtering the (time-varying) input signal and providing a plurality of (time-varying) output signals, each output signal comprising a distinct frequency range of the input signal. The TF transform unit may comprise a Fourier transform unit (e.g. a discrete Fourier transform (DFT) algorithm, a short-time Fourier transform (STFT) algorithm, or a similar algorithm) for converting the time-varying input signal into a (time-varying) signal in the (time-)frequency domain. The frequency domain considered by the hearing aid, from the minimum frequency f min To the maximum frequency f max The frequency range of may include a portion of the typical human hearing range from 20 Hz to 20 kHz, for example a portion of the range from 20 Hz to 12 kHz. Typically, the sampling rate f s Greater than or equal to the maximum frequency f max twice, that is, f s ≥2f max The signals of the forward and / or analysis paths of the hearing aid may be split into NI frequency bands (e.g., of uniform width), where NI is, for example, greater than 5, such as greater than 10, such as greater than 50, such as greater than 100, such as greater than 500, at least parts of which are processed separately. The hearing aid may be adapted to process the signals of the forward and / or analysis paths in NP different frequency channels (NP ≤ NI). The frequency channels may be of uniform or non-uniform width (e.g., increasing width with frequency), overlapping or non-overlapping.

[0086] A hearing aid can be configured to operate in different modes, such as a normal mode and one or more special modes, which can be selected by the user or automatically. The operating modes can be optimized for specific acoustic situations or environments, such as a communication mode, for example, a telephone mode. The operating modes can include a low-power mode, in which the functionality of the hearing aid is reduced (e.g., to save energy), such as disabling wireless communication and / or disabling specific features of the hearing aid.

[0087] The hearing aid may include a plurality of detectors configured to provide status signals related to the current network environment of the hearing aid (e.g., the current acoustic environment), and / or the current state of the user wearing the hearing aid, and / or the current state or operating mode of the hearing aid. Alternatively or additionally, one or more of the detectors may form part of an external device that communicates with the hearing aid (e.g., wirelessly). The external device may include, for example, another hearing aid, a remote control, an audio transmission device, a phone (e.g., a smartphone), an external sensor, etc.

[0088] One or more of the plurality of detectors may operate on a full-band signal (time domain). One or more of the plurality of detectors may operate on a band-split signal ((time-)frequency domain), eg in a limited number of frequency bands.

[0089] The plurality of detectors may include a level detector for estimating the current level of the signal in the forward path. The detector may be configured to determine whether the current level of the signal in the forward path is above or below a given (L-)threshold. The level detector operates on the full-band signal (time domain). The level detector operates on the band-split signal ((time-)frequency domain).

[0090] A hearing aid may include a voice activity detector (VAD) for estimating whether (or with what probability) an input signal (at a given point in time) includes a voice signal. In this specification, a voice signal may be understood to include a speech signal from a human. It may also include other forms of vocalizations (such as singing) produced by the human speech system. The voice activity detector unit may be adapted to classify the user's current acoustic environment as a "voice" or "no-voice" environment. This has the advantage that time periods containing electrical microphone signals of human vocalizations (such as speech) in the user's environment can be identified and thus separated from time periods containing only (or primarily) other sound sources (such as artificially generated noise). The voice activity detector may be adapted to also detect the user's own voice as "voice." Alternatively, the voice activity detector may be adapted to exclude the user's own voice from the "voice" detection.

[0091] A hearing aid may include a self-voice detector for estimating whether (or with what probability) a particular input sound (e.g., voice, such as speech) originates from the voice of a user of the hearing system. The microphone system of the hearing aid may be adapted to be able to distinguish the user's own voice from the voice of another person and possibly from unvoiced sounds.

[0092] The plurality of detectors may include a motion detector such as an accelerometer. The motion detector may be configured to detect movement of the user's facial muscles and / or bones, such as due to speech or chewing (eg, jaw movement), and provide a detector signal indicative of the movement.

[0093] The hearing aid may comprise a classification unit configured to classify a current situation based on an input signal from (at least part of) the detector and possibly other inputs. In this specification, a "current situation" may be defined by one or more of the following:

[0094] a) the physical environment (e.g., including the current electromagnetic environment, such as the presence of electromagnetic signals (including audio and / or control signals) intended or unintended for reception by the hearing aid, or other properties of the current environment other than acoustics);

[0095] b) Current acoustic conditions (input level, feedback, etc.);

[0096] c) the user’s current mode or state (motion, temperature, cognitive load, etc.);

[0097] d) The current mode or status of the hearing aid and / or another device communicating with the hearing aid (selected program, time elapsed since last user interaction, etc.).

[0098] The classification unit may be based on or may comprise a neural network, such as a recurrent neural network, such as a trained neural network.

[0099] Hearing aids may include acoustic (and / or mechanical) feedback control (e.g., suppression) or an echo cancellation system. Adaptive feedback cancellation has the ability to track changes in the feedback path over time. It is typically based on a linear time-invariant filter to estimate the feedback path, but the filter weights are updated over time. The filter updates can be calculated using a stochastic gradient algorithm, including some form of least mean square (LMS) or normalized LMS (NLMS) algorithm. They all have the property of minimizing the difference signal in terms of mean square, with NLMS additionally normalizing the filter updates by the square of the Euclidean norm of a reference signal.

[0100] The hearing aid may also include other appropriate functions for the application in question, such as compression, noise reduction, etc.

[0101] A hearing aid is, for example, a hearing instrument adapted to be positioned at the user's ear or fully or partially positioned in the ear canal, or an earphone, a headset, an ear protection device, or a combination thereof. A hearing system may comprise a loudspeaker amplifier (comprising a plurality of input transducers (e.g., a microphone array) and a plurality of output transducers, such as one or more loudspeakers, and one or more audio (and possibly video) transmitters, such as for use in audio conferencing situations), for example comprising a beamformer filter unit, e.g., providing multiple beamforming capabilities.

[0102] In one aspect, there is provided a use of a hearing aid as described above, in detail in the "Detailed Description" section, and in the claims. The use may be in a system including one or more hearing aids, such as a hands-free telephone system, a teleconferencing system (e.g., including a speakerphone), a public address system, a karaoke system, a classroom amplification system, and the like.

[0103] When appropriately replaced by corresponding processes, some or all structural features of the apparatus described above, described in detail in the "Detailed Description of the Invention" or defined in the claims may be combined with the implementation of the method, and vice versa. The implementation of the method has the same advantages as the corresponding apparatus.

[0104] On the one hand, the present invention also provides a tangible computer-readable medium (data carrier) storing a computer program including program code (instructions), which, when the computer program is run on a data processing system (computer), enables the data processing system to perform (implement) at least part (such as most or all) of the steps of the method described above, described in detail in the "Specific Implementation Method" and defined in the claims.

[0105] By way of example and not limitation, the aforementioned tangible computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage device, or any other medium that can be used to execute or store the desired program code in the form of instructions or data structures and that can be accessed by a computer. As used herein, disks include compact disks (CDs), laser disks, optical disks, digital versatile disks (DVDs), floppy disks, and Blu-ray disks, wherein these disks typically reproduce data magnetically, while these disks can reproduce data optically with lasers. Other storage media include storage in DNA (e.g., in synthetic DNA chains). Combinations of the above disks are also intended to be included within the scope of computer-readable media. In addition to being stored on tangible media, computer programs can also be transmitted via transmission media such as wired or wireless links or networks such as the Internet and loaded into a data processing system to be run at a location different from the tangible media.

[0106] Furthermore, the present invention provides a computer program (product) comprising instructions, which, when executed by a computer, causes the computer to perform (the steps of) the method described above, described in detail in the "Detailed Description of the Invention" and defined in the claims.

[0107] On the one hand, the present invention further provides a data processing system comprising a processor and program code, wherein the program code causes the processor to perform at least part (such as most or all) of the steps of the method described above, described in detail in the "Specific Implementation Methods" and defined in the claims.

[0108] In another aspect, there is provided a hearing aid comprising the device described above, in detail in the "Detailed Description of the Invention" and in the claims, and a hearing system comprising an auxiliary device.

[0109] The hearing system may be adapted to establish a communication link between the hearing aid and the auxiliary device so that information (eg control and status signals, possibly audio signals) can be exchanged or forwarded from one device to the other.

[0110] The auxiliary device may include or may consist of a remote control, a smart phone, or other portable or wearable electronic device such as a smart watch.

[0111] The auxiliary device may consist of or include a remote control for controlling the functions and operation of the hearing aid. The functions of the remote control are implemented in a smartphone, which may run an app that enables the functions of the audio processing device to be controlled via the smartphone (the hearing aid includes a suitable wireless interface to the smartphone, for example based on Bluetooth or some other standardized or proprietary solution).

[0112] The auxiliary device may be constituted by or include an audio gateway device, which is suitable for receiving multiple audio signals (for example from an entertainment device such as a TV or music player, from a telephone device such as a mobile phone, or from a computer such as a PC, a wireless microphone, etc.) and is suitable for selecting and / or combining appropriate signals (or signal combinations) from the received audio signals for transmission to the hearing aid.

[0113] The auxiliary device may consist of or may comprise a further hearing aid.The hearing system may comprise two hearing aids adapted to implement a binaural hearing system, eg a binaural hearing aid system.

[0114] The auxiliary device may consist of or may comprise a charger configured to charge a rechargeable battery of the hearing aid, the charger comprising an integrated circuit charger.

[0115] In another aspect, the present invention further provides a non-transient application, referred to as an App. The App comprises executable instructions configured to run on an auxiliary device to implement a user interface for a hearing aid or hearing system as described above, in detail in the Detailed Description of the Invention, and in the claims. The App can be configured to run on a mobile phone, such as a smartphone, or another portable device that enables communication with the hearing aid or hearing system.

[0116] definition

[0117] As used herein, a hearing aid, such as a hearing instrument, refers to a device adapted to improve, enhance, and / or protect a user's hearing ability by receiving acoustic signals from the user's environment, generating corresponding audio signals, possibly modifying the audio signals, and providing the possibly modified audio signals as audible signals to at least one ear of the user. The audible signals may be provided, for example, in the form of acoustic signals radiated into the user's outer ear and / or acoustic signals transmitted as mechanical vibrations through the bony structure of the user's head and / or through portions of the middle ear to the user's inner ear.

[0118] The hearing aid can be configured to be worn in any known manner, such as as a unit worn behind the ear (with a tube that directs the radiated acoustic signal into the ear canal or with an output transducer, such as a loudspeaker, arranged close to or in the ear canal), as a unit arranged entirely or partially in the auricle and / or ear canal, as a unit connected to a fixed structure implanted in the skull, such as a vibrator, etc. The hearing aid can comprise a single unit or several units that communicate with each other (e.g., acoustically, electrically, or optically). The loudspeaker can be arranged in the housing together with the other components of the hearing aid, or it can itself be an external unit (possibly in combination with a flexible guiding element, such as a dome-shaped element).

[0119] Hearing aids can be adapted to the needs of specific users, such as hearing loss. The configurable signal processing circuitry of the hearing aid can be adapted to apply frequency- and level-dependent compression and amplification of the input signal. The customized frequency- and level-dependent gain (amplification or compression) can be determined during the fitting process by the fitting system based on the user's hearing data, such as an audiogram, using basic fitting principles (e.g., adaptation to speech). The frequency- and level-dependent gain can, for example, be reflected in processing parameters, 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 circuitry of the hearing aid.

[0120] A "hearing system" refers to a system that includes one or two hearing aids. A "binaural hearing system" refers to a system that includes two hearing aids and is adapted to collaboratively provide audible signals to both ears of a user. A hearing system or binaural hearing system may also include one or more "auxiliary devices" that communicate with the hearing aids and influence and / or benefit from the hearing aids' functionality. Such auxiliary devices may include at least one of the following: a charger, a remote control, a remote microphone, an audio gateway device, an entertainment device such as a music player, a wireless communication device such as a mobile phone (e.g., a smartphone) or a tablet, or another device, e.g., including a graphical interface. Hearing aids, hearing systems, or binaural hearing systems may be used, for example, to compensate for hearing loss in hearing-impaired individuals, enhance or protect hearing in hearing-impaired individuals, and / or transmit electronic audio signals to individuals. Hearing aids or hearing systems may, for example, form part of or interact with a public address system, active ear protection system, hands-free phone system, car audio system, entertainment (e.g., television, music playback, or karaoke) system, teleconferencing system, classroom amplification system, and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0121] Various aspects of the present invention will be best understood from the following detailed description in conjunction with the accompanying drawings. For clarity, the drawings are schematic and simplified, showing only the details necessary for understanding the present invention and omitting other details. Throughout the specification, the same reference numerals are used for identical 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 elucidated in conjunction with the following figures, in which:

[0122] Figure 1 schematically illustrates a hearing aid according to an exemplary embodiment of the present invention;

[0123] Figure 2 A flow chart of a method for estimating state of charge according to an exemplary embodiment of the present invention is shown;

[0124] Figure 3 A flow chart illustrating another method for estimating state of charge according to an exemplary embodiment of the present invention is shown;

[0125] Figure 4 schematically illustrates a voltage model that can be used to determine a first estimate;

[0126] Figure 5 Schematically shows Figure 1 The charging voltage, discharging voltage and charging current of the hearing aid are functions of time.

[0127] By the detailed description provided below, the further scope of application of the present invention will be apparent. However, it should be understood that while the detailed description and specific examples indicate the preferred embodiments of the present invention, they are provided for illustrative purposes only. For those skilled in the art, based on the following detailed description, other embodiments of the present invention will be apparent. DETAILED DESCRIPTION

[0128] 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 plurality of different concepts. However, it will be 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 plurality 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 may be implemented using electronic hardware, computer programs or any combination thereof.

[0129] The electronic hardware may include microelectromechanical systems (MEMS), (e.g., application specific) integrated circuits, microprocessors, microcontrollers, digital signal processors (DSPs), field programmable gate arrays (FPGAs), programmable logic devices (PLDs), gating logic, discrete hardware circuits, printed circuit boards (PCBs) (e.g., flexible PCBs), and other suitable hardware configured to perform the various functions described in this specification, such as sensors for sensing and / or recording physical properties of the environment, device, user, etc. A computer program shall be construed broadly to mean instructions, an instruction set, code, a code segment, program code, a program, a subroutine, a software module, an application, a software application, a software package, a routine, a subroutine, an object, an executable, a thread of execution, a program, a function, or the like, whether referred to as software, firmware, middleware, microcode, a hardware description language, or otherwise.

[0130] The present invention relates to the field of hearing aids, in particular to a method for estimating hearing aids, for example in combination with Figure 1 A method of describing the state of charge of a hearing aid.

[0131] Figure 1 A hearing aid HD according to an exemplary embodiment of the present invention is shown. The hearing aid is adapted to provide frequency-dependent gain and / or level-dependent compression and / or frequency transposition of one or more frequency ranges to one or more other frequency ranges (with or without frequency compression) to compensate for a hearing impairment of a user.

[0132] In this example, the hearing aid HD is of a specific type (sometimes referred to as a receiver-in-the-ear or RITE type) that includes a BTE portion adapted to be located at or behind the user's ear and an ITE portion adapted to be located in or at the user's ear canal. The BTE portion and the ITE portion are connected (e.g., electrically) via a connection element IC and internal wiring in the ITE and BTE portions (e.g., see wiring Wx in the BTE portion). Alternatively, the connection element may consist entirely or partially of a wireless link between the BTE and ITE portions.

[0133] The BTE part comprises an input unit comprising two (first) input transducers (eg microphones) M BTE1 ,M BTE2 Each input transducer is used to provide a signal representing an input sound signal S BTE The input unit may further comprise two wireless receivers WLR1, WLR2 (or transceivers) for providing respective directly received auxiliary audio and / or control input signals (and / or enabling transmission of the audio and / or control signals to other devices, such as another hearing aid, a remote control, a processing unit or a telephone). The hearing aid HD comprises a substrate SUB on which a plurality of electronic components are mounted, including a memory MEM for storing, for example, different hearing aid programs (e.g., parameter settings defining these programs, or parameters of algorithms) and / or hearing aid configurations, such as input source combinations M optimized for a plurality of different listening situations. BTE1 ,M BTE2 ,M ITE,env ,M ITE,ed , WLR1, WLR2. In certain operating modes, one or more directly received auxiliary electrical signals may be used together with one or more electrical input signals from the microphones to provide a beamforming signal, which is provided by applying appropriate complex weights to (at least part of) the corresponding signals, for example to provide an enhanced target signal to the user (or to provide an estimate of the user's own voice to another application such as a communication partner or a voice control interface).

[0134] The substrate SUB further comprises a configurable signal processor DSP, such as a digital audio signal processor, e.g., including a processor for applying frequency- and level-dependent gain, for example, to provide hearing loss compensation, beamforming, noise reduction, filter bank functionality, and other digital functions of the hearing device. The configurable signal processor DSP is adapted to access a memory MEM. The configurable signal processor DSP is further configured to process one or more electrical input audio signals and / or one or more directly received auxiliary audio input signals based on currently selected (e.g., automatically selected, e.g., based on one or more sensors, or selected based on input from a user interface) (enabled) hearing aid program / parameter settings. The aforementioned functional units (and other elements) can be divided into circuits and components depending on the application involved (e.g., for size, power consumption, analog-to-digital processing, acceptable latency, etc.), for example, integrated into one or more integrated circuits, or as a combination of one or more integrated circuits and one or more separate electronic components (e.g., inductors, capacitors, etc.). The configurable signal processor DSP provides a processed audio signal, which is intended for presentation to the user. The substrate also includes a front-end IC (FE) for connecting a configurable signal processor (DSP) interface to input and output transducers, etc., typically including interfaces between analog and digital signals (e.g., interfaces to microphones and / or speakers). The input and output transducers can be separate components or integrated with other electronic circuits (e.g., based on MEMS).

[0135] The hearing aid HD further comprises an output unit (e.g. an output transducer) which provides a stimulus perceptible as sound by the user based on the processed audio signal from the processor or a signal derived therefrom. For example, the ITE part comprises an output transducer in the form of a loudspeaker (also called a "receiver") SPK for converting an electrical signal into an acoustic (airborne) signal which (when the hearing aid is mounted on the ear of the user) is directed to the eardrum, thereby providing a sound signal S at the eardrum. ED The ITE part further comprises a guide element DO, such as a dome, for guiding and positioning the ITE part in the ear canal of the user. The ITE part may further comprise a further (first) input transducer, such as a microphone M ITE,env , which is directed towards the environment to provide a signal S representing the input sound at the ear canal ITE The ITE part may also include an additional (second) input transducer such as a microphone M ITE,ed , which is directed towards the eardrum to provide a sound signal representing the sound at the eardrum (S ED =S dir +S HI ) of the (second) electrical input audio signal. Figure 1The dotted arrows in FIG. 3 show the sound propagation from the environment to the residual cavity at the eardrum (denoted as the direct path) via the direct acoustic path through the semi-open dome DO. dir Mark) and the sound from the hearing aid HD (through the sound field S HI The composite sound field S at the eardrum is mixed with ED The sound output of the hearing aid is S HI Sound transmitted directly from the environment to the eardrum may be taken into account (at least in certain operating modes) for modification to provide adaptive noise cancellation (ANC) and / or adaptive occlusion control (AOC).

[0136] In addition to the (acoustic) output and input transducers, the ITE portion may also include other functional elements, such as (additional) detectors, such as electrodes for collecting signals from the user's body (e.g., brain wave signals, temperature indications, blood-related parameters, heartbeat indications, muscle vibrations, etc.). Such detectors may include one or more of the following: an electroencephalogram (EEG) sensor, an electromyogram (EMG) sensor, a motion sensor, a temperature sensor, a photoplethysmogram (PPG) sensor, an electrooculogram (EOG) sensor, etc.

[0137] From the first and / or second input converter M BTE1 ,M BTE2 ,M ITE,env ,M ITE,ed The electrical input signal can be processed in the time domain or in the (time-)frequency domain (or partly in the time domain and partly in the frequency domain, as is advantageous for the application in question).

[0138] The hearing aid HD comprises a rechargeable battery BAT, for example based on lithium-ion battery technology, for example for powering the electronics of the BTE part and possibly the ITE part. Furthermore, the hearing aid HD may comprise a battery circuit including a current accumulator (also called a coulomb counter or fuel gauge).

[0139] The BTE part may include a connector (e.g., a DAI or USB connector) for connecting "externals" with additional functions (e.g., FM external devices or additional batteries, etc.), programming devices, chargers, or separate processing devices to the hearing aid HD.

[0140] The hearing aid HD is configured to perform the method for estimating the state of charge according to the invention, for example in combination with Figure 2 Described methods and combinations Figure 3 At least some of the steps of the method described.

[0141] Figure 2 A flowchart of the steps of a method for estimating state of charge according to an exemplary embodiment of the present invention is shown.

[0142] The method includes step 230 of determining a state of charge (SoC) value based on a weighted combination of a first state of charge estimate value (SoCV) and a second state of charge estimate value (SoCC).

[0143] The first state-of-charge estimate value SoCV is determined using a voltage model. In addition, the second state-of-charge estimate value SoCC is determined by tracking the charge flow of the battery BAT or by tracking the energy flow of the battery.

[0144] Furthermore, a combination of the first weight of the first estimated value and the second weight of the second estimated value corresponds to a maximum weight.

[0145] The method may further include: step 210 , determining a first state of charge estimation value SOCv using a voltage model; and / or step 220 , determining a second state of charge estimation value SOCc by tracking a charge flow or an energy flow of the battery BAT.

[0146] Figure 3 A flowchart illustrating the steps of another method for estimating state of charge according to an exemplary embodiment of the present invention is shown.

[0147] The method may include step 310 of determining a first state of charge estimate SOCV using a voltage model.

[0148] The voltage model is typically a mapping between the battery voltage and the discharge capacity of the battery BAT (also referred to as the discharge charge of the battery), i.e., the charge flowing out of the battery BAT or the actual charge stored in the battery BAT. This mapping is, for example, a predetermined bijective mapping between the battery voltage and the charge flowing out of the battery BAT, such as Figure 4 Voltage model.

[0149] Figure 4 A voltage model that can be used to determine the first estimated value SOC V is schematically shown. The voltage model is a discharge curve 400 of a battery BAT of a hearing aid HD, representing the battery voltage as a function of the discharge capacity.

[0150] The discharge curve 400 is generally predetermined due to capacity-voltage variations across different types of batteries.

[0151] Additionally, the discharge curve 400 may be updated throughout the useful life of the battery BAT as there are capacity-voltage variations throughout the useful life.

[0152] For example, an initial predetermined discharge curve (which may be a typical discharge curve for the battery type of the battery BAT) is gradually updated, for example using input from a current accumulator that tracks the charge discharged over time, temperature changes determined using a temperature sensor, and the battery voltage that may be determined by the integrated circuit charger of the hearing aid HD.

[0153] The actual charging voltage may be lowered by temperature. Additionally, updates may be disabled if the temperature is below a temperature threshold, such as 15 degrees Celsius, or if the charge or consumed energy after startup is above a charge threshold (e.g., 0.175 mAh), or if the battery voltage is below a voltage threshold (e.g., 3850 mV).

[0154] Figure 4 The discharge curve is a bijective mapping with linear interpolation between the voltage level of the battery voltage and the actual charge stored on the battery BAT from a maximum voltage, in this example the maximum lithium-ion voltage of the battery type used.

[0155] If the battery is replaced, the voltage model is usually replaced by a voltage model corresponding to the new battery, for example by another initial discharge curve corresponding to the new battery, which is then gradually updated.

[0156] The voltage model can also be a mapping (e.g., a predetermined bijective mapping) between battery voltage and discharge energy of the battery BAT (e.g., discharge energy in mWh). Such a mapping can also be predetermined (because it varies across different types of batteries), replaced when the battery is replaced, and updated over the life of the battery BAT (because it varies over the life of the battery). Updates can be disabled if the temperature is below a temperature threshold, if the energy consumed after startup is above an energy threshold, or if the battery voltage is below a voltage threshold.

[0157] Return to Figure 3 In the method shown, step 310 of determining the first state of charge estimate SoCV may be performed differently depending on whether the battery is in a charging state or a discharging state to account for voltage differences and / or redistribution effects, which may result in an initial overshoot of the first estimate SoCV based on the voltage when changing from charging to discharging, and an initial undershoot when changing from discharging to charging.

[0158] More specifically, the voltage during charge is higher than during discharge due to changes in the electrochemistry and diffusion of lithium ions. This change in state between charge and discharge leads to a redistribution effect, which involves the slow migration of lithium ions. This redistribution can span several hours, affecting the battery voltage. However, most redistribution occurs within an hour, with the majority of Alpha occurring almost immediately.

[0159] Therefore, the step 310 of determining a first state of charge estimate value SOCV may include a step 312 of determining whether the battery is in a charging state or a discharging state.

[0160] When the battery is in a discharging state, at step 314 , a first state of charge estimation value SOCV is determined using the voltage model Vmod and the battery voltage Vbat.

[0161] More specifically, the current battery voltage Vbat is obtained, and the first estimated value SoCV corresponds to a discharge capacity value obtained using the current battery voltage Vbat and the voltage model Vmod.

[0162] While the battery is in the state of charge, at step 316 , a first state of charge estimate SOCV is determined using the voltage model Vmod and the modeled battery voltage potential difference ΔV between charging and discharging.

[0163] The voltage potential difference ΔV is typically modeled as the voltage increase due to the charging current flowing through the resistor, with an additional offset to account for the redistribution effects that occur after charging.

[0164] For example, the first state of charge estimation value SOC V is determined using the following formula:

[0165]

[0166] in:

[0167] -SoCV is the first state of charge estimate

[0168] -f_learn is the voltage model

[0169] -Vbat is the battery voltage

[0170] -i_charge is the charging current flowing into the battery

[0171] -R_charge is the modeled charging resistance

[0172] -Alpha is a predetermined value

[0173] -V_relax is another predetermined value that models an additional offset.

[0174] In this formula, the voltage potential difference ΔV is modeled by the i_charge*R_charge-Alpha*V_relax portion.

[0175] The additional offset V_relax is generally constant and accounts for the voltage drop that occurs after charging is complete due to electrochemical redistribution. The additional offset V_relax corresponds to the battery voltage drop when the charging current applied to the battery is no longer applied.

[0176] The alpha value scales the additional offset Vrelax to the amount of voltage drop that occurs almost immediately. The alpha value can be further scaled to account for variations due to different battery voltages. The alpha value can be predetermined and / or fixed.

[0177] Alpha may depend on the battery voltage Vbat, with the value of Alpha typically being higher at very low voltages:

[0178]

[0179] Therefore, Alpha provides the ability to scale the V_relax value to account for variations in the amount of redistribution at different voltage levels.

[0180] In a simple implementation, Alpha may also be set to 1, thereby ignoring variations and providing a rougher approximation.

[0181] At step 320 , a second state of charge estimate, SOC, may also be determined by tracking the charge flow of the battery or by tracking the energy flow of the battery.

[0182] When the battery BAT is in a discharge state, the coulomb counter is used to track the charge flow or energy flow of the battery BAT. For example, when the battery BAT is in a charge state, the charge flow is determined by integrating the current of the integrated circuit charger using the coulomb counter.

[0183] When tracking charge flow, a second state-of-charge estimate can be determined using the following formula:

[0184] SoCC(t)=SoC(0)+∫0 t i_batdt

[0185] in:

[0186] -SoCC is the second state of charge estimate

[0187] - SoC(0) is the value of the state of charge after changing from the charging state to the discharging state or from the discharging state to the charging state

[0188] -i_bat is the battery current

[0189] -t is the time since the state changed.

[0190] When tracking energy flow, the second state of charge estimate can be determined using the following formula:

[0191] SoCC(t)=SoC(0)+∫0 t i_bat*Vbatdt

[0192] in:

[0193] -SoCC is the second state of charge estimate

[0194] - SoC(0) is the value of the state of charge after changing from the charging state to the discharging state or from the discharging state to the charging state

[0195] -i_bat is the battery current

[0196] -t is the time since the state changed

[0197] -Vbat is the battery voltage.

[0198] In both cases, the battery current can be determined using the following formula:

[0199]

[0200] in:

[0201] -i_bat is the battery current

[0202] -i_charge is the charging current flowing into the battery during charging

[0203] -i_discharge is the discharge current that flows from the battery during discharge.

[0204] The method comprises step 330 of determining a value of the state of charge SoC based on a weighted combination of a first state of charge estimate value SoCV and a second state of charge estimate value SoCC.

[0205] The state of charge (SoC) value can be determined using the following formula:

[0206] SoC=SoCV*Wv+SoCC*Wc, where Wv=Wmax–Wc, Wmin≤Wv≤Wmax, Wmin≤Wc≤Wmax

[0207] in:

[0208] -SoC is the state of charge

[0209] -SoCV is the first state of charge estimate

[0210] -Wv is the first weight

[0211] -SoCC is the second state of charge estimate

[0212] -Wc is the second weight

[0213] -Wmin is the minimum weight

[0214] -Wmax is the maximum weight.

[0215] Wmin is equal to 0, for example, and Wmax is equal to 1 or 100.

[0216] Determining the state of charge value step 330 may include determining whether one or more state conditions of the battery BAT are satisfied, such as determining whether an end condition EC is satisfied at step 332 and / or determining whether a state change condition CC is satisfied at step 335 .

[0217] The end condition EC is, for example, that charging is almost completed or that the shutdown voltage is almost reached.

[0218] When the end condition EC is met, the second weight Wc is reduced or switched towards the minimum weight Wmin in step 334. This causes the state of charge SoC to reach its maximum value when charging is complete and the state of charge SoC to reach its minimum value when the hearing aid HD is shut down due to the shutdown voltage level.

[0219] For example, to determine whether charging is almost complete, it is determined that the battery voltage is substantially constant, that is, the battery is in constant voltage mode (see Figure 5 When it is determined that charging is almost complete, in step 334, the second weight Wc is generally reduced as the charging current decreases in the constant voltage mode, and for example, continuously reduced.

[0220] To determine whether the shutdown voltage has been nearly reached, it is determined whether the battery voltage is below a battery voltage threshold, such as a predetermined low battery voltage threshold. When it is determined that the shutdown voltage has been nearly reached, i.e., when the battery voltage is determined to be below the battery voltage threshold, at step 334, the second weight Wc is typically decreased while the battery voltage decreases between the battery voltage threshold and the shutdown voltage, for example, by applying a linear scale to the second weight Wc.

[0221] The state change condition CC is a change of the battery from a charging state to a discharging state or a change from a discharging state to a charging state.

[0222] In step 335 , it is determined whether the state change condition CC is satisfied. When the state change condition CC is satisfied and the end condition EC is not satisfied, in step 336 , the second weight Wc is generally set to be substantially equal to the maximum weight Wmax.

[0223] This enables the use of a second state of charge estimate, SoCC, which in this case enables a more accurate estimate of the state of charge, SoC, to be obtained, since counting / tracking of the charge / energy flow of the battery is used. The use of the initial value, SoC(0), which is the state of charge value immediately before the change of state, ensures consistency in the state of charge reporting during the change of state.

[0224] When the state change condition CC is satisfied and the end condition EC is not satisfied, it may also be determined whether the battery is fully charged. If the battery is fully charged, in step 336, the second weight Wc may be set to be substantially equal to the maximum weight Wmax. If the battery is not fully charged, the first weight Wv may be set to be substantially equal to the maximum weight Wmax.

[0225] When neither the state change condition CC nor the end condition EC is satisfied, the second weight Wc continues to decrease in step 337, typically following the gradual change of the redistribution effect following a possible state change. For example, the second weight Wc continues to decrease as a function of the relaxation voltage after charging, and more specifically, following the inverse of the relaxation voltage after charging. The relaxation voltage is the drop in battery voltage caused by the redistribution effect when the battery is unloaded after charging.

[0226] At step 338 , the first weight Wv may then be determined based on the second weight Wc using the formula Wv=Wmax−Wc.

[0227] Of course, instead of determining the second weight Wc in steps 334, 336, or 337, the first weight Wv can also be determined. More specifically, when the end condition EC is met, the first weight Wv increases toward the maximum weight Wmax. When the state change condition CC is met and the end condition EC is not met, in step 336, the first weight Wv is set to be substantially equal to the maximum weight Wmax. When neither the state change condition CC nor the end condition EC is met, in step 337, the first weight Wv continues to increase. In step 338, the second weight Wc can be determined based on the first weight Wv using the formula Wv = Wmax – Wc.

[0228] In step 339 , the value of the state of charge SoC is determined using the first weight Wv and the first estimated value SoCV and / or the second weight Wc and the second estimated value SoCC.

[0229] Steps 332 - 338 of determining the first weight Wv and / or the second weight Wc may be performed before step 310 of determining the first estimated value SoCV and / or step 320 of determining the second estimated value SoCC.

[0230] The step 310 of determining the first estimated value SoCV may not be performed when the state change condition is satisfied, because the first estimated value SoCV may not be taken into account and the associated first weight is substantially equal to zero.

[0231] The step 320 of determining the second estimated value SoCC may not be performed when the end condition is met, because the first estimated value SoCC may not be taken into account and the associated second weight is substantially equal to zero.

[0232] The estimated state of charge may be used to determine the battery level of the hearing aid, thereby providing the user with the battery level of the hearing aid.

[0233] In another embodiment, step 320 of determining the second state-of-charge estimate SoCC and step 330 of determining the state-of-charge (SoC) value based on a weighted combination of the first state-of-charge estimate SoCCV and the second state-of-charge estimate SoCCV are not performed. In this embodiment, only the first estimate SoCCV determined in step 310 is used to determine the state-of-charge (SoC). More specifically, when the battery is in a discharged state, the state-of-charge (SoC) corresponds to the first estimate SoCCV determined in step 314, and when the battery is in a charged state, the state-of-charge (SoC) corresponds to the first estimate SoCCV determined in step 316.

[0234] The structural features of the apparatus described above, described in detail in the "Detailed Description of the Invention" and defined in the claims may be combined with the steps of the method of the present invention when appropriately replaced by corresponding processes.

[0235] Unless expressly stated otherwise, the singular forms "a", "the" and "the" used herein include the plural form (i.e., having the meaning of "at least one"). It should be further understood that the terms "having", "including" and / or "comprising" used in the specification indicate the presence of the described features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or combinations thereof. It should be understood that, unless expressly stated otherwise, when an element is referred to as being "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or there may be an intermediate intervening element. The term "and / or" as used herein includes any and all combinations of one or more listed related items. Unless expressly stated otherwise, the steps of any method disclosed herein do not have to be performed in the exact order disclosed.

[0236] It should be understood that references in this specification to "an embodiment," "an embodiment," "an aspect," or features that "may" include, mean that the specific features, structures, or characteristics described in conjunction with that embodiment are included in at least one embodiment of the present invention. Furthermore, the specific features, structures, or characteristics may be combined as appropriate in one or more embodiments of the present invention. The foregoing description is provided to enable those skilled in the art to practice the various aspects described herein. Various modifications will be apparent to those skilled in the art.

[0237] The claims are not limited to the aspects shown herein, but rather have the full scope consistent with the claim language in which, 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.

Claims

1. A method for estimating the state of charge of a hearing aid comprising a rechargeable battery, the method comprising: determining a state of charge value based on a weighted combination of a first state of charge estimate determined using a voltage model and a second state of charge estimate determined by tracking charge flow or energy flow of the battery; wherein a combination of the first weight of the first state of charge estimate and the second weight of the second state of charge estimate corresponds to a maximum weight; Determining the first state of charge estimate includes: - Determine whether the battery is in a charging or discharging state; - determining a first state of charge estimate using the voltage model and the battery voltage when the battery is in a discharged state; - While the battery is in a state of charge, determining a first state of charge estimate using the voltage model and the modeled voltage potential difference between charging and discharging.

2. The method according to claim 1, wherein The voltage potential difference is modeled as the voltage increase due to the charging current flowing through the resistor, plus an additional offset to account for the redistribution effects that occur after charging.

3. The method according to claim 1, wherein The first state of charge estimate is determined using the following formula: in: -SoCV is the first state of charge estimate -f_learn is the voltage model -Vbat is the battery voltage -i_charge is the charging current flowing into the battery -R_charge is the modeled charging resistance -Alpha is a predetermined value -V_relax is another predetermined value that models an additional offset.

4. The method according to claim 1, wherein The second state of charge estimate is determined using one of the following formulas: SoCC(t)=SoC(0)+∫0 t i_bat dt or SoCC(t)=SoC(0)+∫0 t i_bat*Vbat dt in: -SoCC is the second state of charge estimate - SoC(0) is the value of the state of charge after changing from the charging state to the discharging state or from the discharging state to the charging state -i_bat is the battery current -t is the time since the state changed -Vbat is the battery voltage.

5. The method according to claim 1, wherein When the end condition is met, the second weight is decreased towards the minimum weight and / or the first weight is increased towards the maximum weight.

6. The method according to claim 5, wherein: When the state change condition is satisfied and the end condition is not satisfied, the second weight is set to be substantially equal to the maximum weight and / or the first weight is set to be substantially equal to the minimum weight.

7. The method according to claim 5, further comprising, when a state change condition is satisfied and an end condition is not satisfied: - Determine if the battery is fully charged; - if the battery is fully charged, setting the second weight to be substantially equal to the maximum weight; and - If the battery is not fully charged, setting the first weight to be substantially equal to the maximum weight.

8. The method according to claim 5, wherein When the state change condition and the end condition are not satisfied, the second weight continues to decrease and / or the first weight continues to increase.

9. A hearing aid configured to compensate for hearing loss of a user wearing the hearing aid, the hearing aid comprising: - an input unit configured to receive an acoustic signal and convert the acoustic signal into an input signal; - a signal processor configured to process an input signal having a hearing loss profile of a user; - an output unit configured to transmit the processed signal having the hearing loss curve into an ear of the user; and - Rechargeable batteries; Wherein, the signal processor is configured to perform the method according to claim 1.

10. A system comprising a hearing aid according to claim 9 and a charger configured to charge a rechargeable battery of the hearing aid.

11. A data processing system comprising a processor and a program code, wherein the program code causes the processor to execute at least some of the steps of the method according to claim 1.

12. A computer program product comprising a computer program containing instructions for causing a computer to perform the method according to claim 1 when the computer program is run by a computer.

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