Method for detecting conditions of a hearing device

Abstract

A computer-implemented method for detecting a condition of a hearing device, the hearing device comprising an electro-acoustic transducer having at least two input terminals, a nozzle connected to the transducer, and a controller, the method comprising: generating an electrical signal for reproduction by the transducer; estimating a first voltage at a first frequency between the input terminals of the transducer by applying an electrical signal to the transducer; estimating a second voltage at a second frequency by applying an electrical signal between the input terminals of the transducer, where the second frequency is higher than the first frequency; determining, by the controller, a difference between the first voltage and the second voltage; assigning a first state to the condition if the difference is below a first threshold; assigning a second state to the condition if the difference value is above a second threshold value, the second threshold value being above the first threshold value; and assigning a third state to the condition if the difference is between the first threshold and the second threshold.

Description

Technical Field

[0001] The present invention relates to audio data processing, sometimes referred to as audio signal processing. More specifically, the present disclosure relates to a computer-implemented method for detecting the condition of a hearing device, a hearing device, and a system including the hearing device and an external device communicatively coupled to the hearing device. Background Art

[0002] In the past few years, significant progress has been made in the development of hearing devices. For example, by being able to reduce the size of components, it has been possible to provide ear-worn hearing devices that, despite their small size, are capable of providing a high-quality listening experience. For hearing aids, which are one type of hearing device, this development has made it possible to provide receiver-in-the-ear (RIE) devices and behind-the-ear (BTE) devices that users can wear for long periods without discomfort and without affecting their hearing assistance capabilities.

[0003] Although using these types of hearing devices has several advantages, the problem with partially or fully placing them in the ear canal is that earwax (cerumen) may clog the hearing device. For example, since the spout (sometimes referred to as the receiver outlet) is placed in the earplug or dome or is connected to the sound tube, providing a sound path for sound waves from the receiver, the spout may become clogged. Due to the obstruction of the sound waves, the sound waves cannot reach the user correctly, resulting in a weakened or non-existent hearing assistance and / or a deteriorated hearing experience.

[0004] However, the clogging of the spout of a hearing device by earwax is not a new problem, and different solutions have been proposed. A common solution is to provide a so-called earwax filter on the spout. By having such a filter, sound waves are allowed to pass through, but earwax is blocked from entering the spout and the interior of the hearing device. Once the filter becomes clogged, i.e., once the amount of earwax present in the filter reaches a certain level such that the collected earwax obstructs the sound waves, the filter needs to be replaced. Since the filter is small, the operation of replacing the filter may be cumbersome for some people. In some cases, for example, in the case of hearing aids for children or the elderly, those who experience a performance degradation may also have difficulty informing someone who can help them about the performance degradation.

[0005] In addition to the filter becoming clogged, there is also a risk of the filter falling off, which may not have an immediate effect but may cause earwax to enter the hearing device and cause its interior to become clogged. Clogging of the interior of the hearing device often requires opening the hearing device as part of the cleaning process. Such an operation may require special tools, and it is generally recommended that such an operation be performed by a trained technician to ensure that the hearing device is not damaged during the cleaning operation.

[0006] EP 2 039 216 A1 proposes different methods for detecting the presence of earwax in the sound outlet of a hearing device. In this document, it is disclosed that the impedance can be measured, and if earwax is present, the impedance may change.

[0007] Although there are currently solutions to reduce the impact of earwax on hearing devices and methods for detecting the presence of earwax, there is still a need for methods and devices that can detect the presence of earwax more accurately and reliably, enabling more timely measures to be taken. Summary of the Invention

[0008] One objective is to at least partially overcome one or more of the above limitations of the prior art. Specifically, one objective is to provide a method that can continuously and efficiently monitor a hearing device, enabling the detection of one or more conditions that degrade the performance of the hearing device. An example of such a condition is that the sound outlet of the receiver of the hearing device is partially or completely blocked by earwax.

[0009] According to a first aspect, there is provided a computer-implemented method for detecting the condition of a hearing device. The hearing device may include an electroacoustic transducer having at least two input terminals, a sound outlet connected to the transducer, and a controller. The method may include: generating an electrical signal for reproduction by the transducer; estimating a first voltage at a first frequency between the input terminals of the transducer by applying the electrical signal to the transducer; estimating a second voltage at a second frequency by applying the electrical signal, where the second frequency is higher than the first frequency; determining, by the controller, the difference between the first voltage and the second voltage; assigning a first state to the condition if the difference is below a first threshold; assigning a second state to the condition if the difference is above a second threshold, where the second threshold is higher than the first threshold; and assigning a third state to the condition if the difference is between the first threshold and the second threshold.

[0010] By adapting the first frequency and the second frequency to the transducer, at least three different states can be detected. For example, it can be detected that the sound outlet is unobstructed (i.e., there is no blockage), partially blocked, or completely blocked. In this way, the performance of the hearing device can be monitored over time, and actions required to overcome an undesirable condition (such as a blocked sound outlet) can be detected at an early stage.

[0011] The hearing device may be a receiver-in-ear (RIE) hearing device.

[0012] The first voltage and the second voltage may respectively reflect a first electrical input impedance and a second electrical input impedance.

[0013] The electroacoustic transducer may be a balanced armature transducer.

[0014] The frequency can be an audio frequency, where the first frequency is below 2500 Hz and the second frequency is above 2500 Hz.

[0015] The first frequency and the second frequency can be selected based on the position where the transducer has a significant electrical input impedance resonance.

[0016] The electrical signal can be a preset audio signal stored in a memory included in the hearing device.

[0017] The mouth of the transducer can be equipped with a filter for preventing earwax from transferring into the mouth. The method can further include: assigning a fourth state to the condition when the difference is below a third threshold, where the third threshold is lower than the first threshold.

[0018] The hearing device can be arranged to communicate with an external device (e.g., a mobile phone). The method can further include: sending a "clear mouthpiece" notification signal from the hearing device to the external device if the first state is assigned to the condition; sending a "blocked mouthpiece" notification signal from the hearing device to the external device if the second state is assigned to the condition; sending a "partially blocked mouthpiece" notification signal from the hearing device to the external device if the third state is assigned to the condition; and / or sending a "missing filter" notification signal from the hearing device to the external device if the fourth state is assigned to the condition.

[0019] According to a second aspect, there is provided a hearing device including an electroacoustic transducer having at least two input terminals, a mouthpiece connected to the transducer, and a controller. The controller can be configured to: generate an electrical signal for reproduction by the transducer; estimate a first voltage at a first frequency between the input terminals of the electroacoustic transducer in the hearing device by applying the electrical signal; estimate a second voltage at a second frequency in the hearing device by applying the electrical signal between the input terminals of the electroacoustic transducer, where the second frequency is higher than the first frequency; determine a difference between the first voltage and the second voltage; assign a first state to the condition when the difference is below a first threshold; assign a second state to the condition when the difference is above a second threshold, where the second threshold is higher than the first threshold; and assign a third state to the condition when the difference is between the first threshold and the second threshold.

[0020] The same features and advantages presented above with respect to the first aspect also apply to this aspect.

[0021] The hearing device can be an in-the-ear receiver (RIE) hearing device.

[0022] The electroacoustic transducer can be a balanced armature transducer.

[0023] The electrical signal can be a preset audio signal stored in the memory.

[0024] According to a third aspect, a system is provided that includes a hearing device and an external device according to the second aspect, wherein the hearing device is arranged to transfer a status of a condition to the external device.

[0025] According to a fourth aspect, a computer program product is provided that includes instructions which, when executed by a controller, cause the controller to perform the method according to the first aspect.

[0026] The hearing device can be a hearing aid, i.e., one or two devices configured to alleviate hearing loss and worn by a user in one or both ears. As is well known, a hearing device can be equipped with: one or more microphones, a processor, and a memory for processing data received by the microphones; and one or more transducers for generating sound waves to the user of the hearing device. In the case of two hearing devices, they can be configured to communicate with each other such that the hearing experience can be improved. The hearing device can also be configured to communicate with an external device (e.g., a mobile phone), in which case audio input data can be captured by the mobile phone and transmitted to the hearing device. The mobile phone itself can also constitute a hearing device.

[0027] The term "hearing device" should not be understood in this context as a device only for use by persons with hearing impairments, but rather as a device for use by anyone who wants to perceive speech more clearly (i.e., improve speech intelligibility). When not used to provide audio output data, the hearing device can be used for listening to music or similar purposes. In other words, the hearing device can be earbuds, headphones, or other similar devices configured such that when audio input data is received, it can be converted into the audio output data described herein.

[0028] The hearing device can also form part of a device not only for listening purposes. For example, the hearing device can be a pair of smart glasses. In addition to converting audio input data into the audio output data described herein and providing the resulting sound via, for example, the temple pieces of the smart glasses, the glasses can also present visual information to the user by using the lenses as a heads-up display.

[0029] The hearing device can be configured to be worn by a user. The hearing device can be arranged at, on, above, in, within the ear canal, behind, and / or within the concha of the user's ear, i.e., the hearing device is configured to be worn in, on, above, and / or at the user's ear. The user can wear two hearing devices, one on each ear. The two hearing devices can be connected, for example, wirelessly and / or wired, to form a binaural hearing aid system.

[0030] A hearing device can be an audible device, such as a headset, earphone, earplug, hearing aid, personal sound amplification product (PSAP), over-the-counter (OTC) hearing device, hearing protection device, general-purpose hearing device, custom hearing device, or another head-worn hearing device. The hearing device can include both prescription and over-the-counter devices.

[0031] Hearing devices can come in a variety of housing styles or dimensions. Some of these dimensions are earplugs, ear-hook headphones, or ear-loop headphones. Those skilled in the art are well aware of the different types of hearing devices and the different options for positioning the hearing device in, on, above, and / or around the ear of the hearing device wearer. The hearing device (or a pair of hearing devices) can be custom, standard, open, and / or closed.

[0032] A hearing device can include one or more input transducers. The one or more input transducers can include one or more microphones. The one or more input transducers can include one or more vibration sensors configured to detect bone vibrations. The one or more input transducers can be configured to convert an acoustic signal into a first electrical input signal. The first electrical input signal can be an analog signal. The first electrical input signal can be a digital signal. The one or more input transducers can be coupled to one or more analog-to-digital converters configured to convert the analog first input signal into a digital first input signal.

[0033] A hearing device can include one or more antennas configured for wireless communication. The one or more antennas can include electrical antennas. The electrical antennas can be configured for wireless communication at a first frequency. The first frequency can be higher than 800 MHz, preferably with a wavelength between 900 MHz and 6 GHz. The first frequency can be 902 MHz to 928 MHz. The first frequency can be 2.4 to 2.5 GHz. The first frequency can be 5.725 GHz to 5.875 GHz. The one or more antennas can include magnetic antennas. The magnetic antennas can include magnetic cores. The magnetic antennas can include coils. The coils can be wound around the magnetic cores. The magnetic antennas can be configured for wireless communication at a second frequency. The second frequency can be lower than 100 MHz. The second frequency can be between 9 MHz and 15 MHz.

[0034] A hearing device may include one or more wireless communication units. The one or more wireless communication units may include one or more wireless receivers, one or more wireless transmitters, one or more transmitter-receiver pairs, and / or one or more transceivers. At least one of the one or more wireless communication units may be coupled to one or more antennas. The wireless communication unit may be configured to convert a wireless signal received by at least one of the one or more antennas into a second electrical input signal. The hearing device may be configured for wired / wireless audio communication, e.g., such that the user can listen to media (e.g., music or radio) and / or such that the user can make a phone call.

[0035] The wireless signal may originate from one or more external sources and / or external devices, such as a paired microphone device, a wireless audio transmitter, a smart computer, and / or a distributed microphone array associated with a wireless transmitter. The wireless input signal may originate from another hearing device (e.g., as part of a binaural hearing system) and / or from one or more accessory devices (e.g., a smartphone and / or a smartwatch).

[0036] The hearing device may include a processing unit. The processing unit may be configured to process the first and / or second electrical input signals. Processing may include: compensating for the user's hearing loss, i.e., applying a frequency-dependent gain to the input signal according to the user's frequency-dependent hearing impairment. Processing may include: performing feedback cancellation, beamforming, tinnitus reduction / masking, noise reduction, noise cancellation, speech recognition, bass adjustment, treble adjustment, and / or processing of user input. The processing unit may be a processor, an integrated circuit, an application, a functional module, etc. The processing unit may be implemented in a signal processing chip or a printed circuit board (PCB). The processing unit may be configured to: provide a first electrical output signal based on the processing of the first and / or second electrical input signals. The processing unit may be configured to: provide a second electrical output signal. The second electrical output signal may be based on the processing of the first and / or second electrical input signals.

[0037] The hearing device may include an output transducer. The output transducer (also referred to herein as an electroacoustic transducer or receiver) may be coupled to the processing unit. The output transducer may be a speaker. The output transducer may be configured to: convert the first electrical output signal into an acoustic output signal. The output transducer may be coupled to the processing unit via a magnetic antenna.

[0038] In an embodiment, the wireless communication unit may be configured to: convert the second electrical output signal into a wireless output signal. The wireless output signal may include synchronization data. The wireless communication unit may be configured to: transmit the wireless output signal via at least one of the one or more antennas.

[0039] A hearing device may include a digital-to-analog converter configured to convert a first electrical output signal, a second electrical output signal, and / or a wireless output signal into an analog signal.

[0040] A hearing device may include a vent. The vent is a physical passage, such as a duct or a tube, which is placed mainly to provide pressure equalization on a housing placed in the ear (e.g., an ITE hearing device, the ITE unit of a BTE hearing device, a CIC hearing device, an RIE hearing device, a RIC hearing device, a MaRIE hearing device, or a dome / ear mold). The vent may be a pressure vent with a small cross-sectional area, which is preferably acoustically sealed. The vent may be an acoustic vent configured to eliminate blockages. The vent may be an active vent such that the vent can be opened or closed during use of the hearing device. The active vent may include a valve.

[0041] A hearing device may include a power source. The power source may include a battery providing a first voltage. The battery may be a rechargeable battery. The battery may be a replaceable battery. The power source may include a power management unit. The power management unit may be configured to convert the first voltage into a second voltage. The power source may include a charging coil. The charging coil may be provided by a magnetic antenna.

[0042] A hearing device may include a memory, including memory in volatile and non-volatile forms.

[0043] A hearing device may include one or more antennas for radio frequency communication. The one or more antennas may be configured to operate in the ISM band. One of the one or more antennas may be an electrical antenna. One of the one or more antennas may be a magnetic induction coil antenna. Magnetic induction or near-field magnetic induction (NFMI) typically provides communication in a frequency range between 2 MHz and 15 MHz, including the transmission of voice, audio, and data. At these frequencies, electromagnetic radiation propagates through and around the human head and body without significant loss in tissue.

[0044] The magnetic induction coil may be configured to operate at a frequency below 100 MHz during use, such as below 30 MHz, such as below 15 MHz. The magnetic induction coil may be configured to operate in a frequency range between 1 MHz and 100 MHz, such as between 1 MHz and 15 MHz, such as between 1 MHz and 30 MHz, such as between 5 MHz and 30 MHz, such as between 5 MHz and 15 MHz, such as between 10 MHz and 11 MHz, such as between 10.2 MHz and 11 MHz. The frequency may also include the range from 2 MHz to 30 MHz, such as from 2 MHz to 10 MHz, such as from 2 MHz to 10 MHz, such as from 5 MHz to 10 MHz, such as from 5 MHz to 7 MHz.

[0045] The electrical antenna can be configured to operate at a frequency of at least 400 MHz, such as at least 800 MHz, such as at least 1 GHz, such as at a frequency between 1.5 GHz and 6 GHz, such as at a frequency between 1.5 GHz and 3 GHz, such as at a frequency of 2.4 GHz. The antenna can be optimized to operate at a frequency between 400 MHz and 6 GHz, such as between 400 MHz and 1 GHz, between 800 MHz and 1 GHz, between 800 MHz and 6 GHz, between 800 MHz and 3 GHz, etc. Thus, the electrical antenna can be configured to operate in the ISM band. The electrical antenna can be any antenna capable of operating at these frequencies, and the electrical antenna can be a resonant antenna, such as a monopole antenna, such as a dipole antenna, etc. The length of the resonant antenna can be λ / 4 ± 10% or any multiple thereof, where λ is the wavelength corresponding to the emitted electromagnetic field.

[0046] The present invention relates to different aspects, including the hearing devices and systems and corresponding device components described above and below. Each aspect provides one or more benefits and advantages associated with the description of the first-mentioned aspect, and each aspect has one or more embodiments corresponding to the embodiments described in and / or disclosed in the appended claims associated with the first-mentioned aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Those skilled in the art will readily appreciate the above and other features and advantages from the following detailed description of its exemplary embodiments with reference to the accompanying drawings, in which:

[0048] Figure 1 is a graph showing the variation of the electrical input impedance measured at two input terminals of a transducer with frequency for different degrees of blockage.

[0049] Figure 2 is a graph showing the variation of the impedance difference for two frequencies with the degree of blockage.

[0050] Figure 3A is a graph showing the white noise test signals that can be used to determine two frequencies.

[0051] Figure 3B is a graph showing, for a hearing aid with an unblocked sound outlet, the measured input impedance varying with frequency caused by the Figure 3A test signal shown in

[0052] Figure 3C is a graph showing, for a hearing aid with a partially blocked sound outlet, the measured input impedance varying with frequency caused by the Figure 3A test signal shown in

[0053] Figure 3Dis a graph showing the measured input impedance as a function of frequency for a hearing aid with a blocked sound outlet, caused by the Figure 3A test signal shown in

[0054] Figure 4A The upper part of shows a test signal including two sine waves of different frequencies, and the lower part shows the root mean square (RMS) voltage values of the two sine waves measured at the input terminals for a hearing aid with an unblocked sound outlet.

[0055] Figure 4B The upper part of shows a test signal including two sine waves of different frequencies, and the lower part shows the RMS voltage values measured at the input terminals in the case of a blocked sound outlet.

[0056] Figure 5 is a graph showing the change in impedance difference for two selected frequencies as a function of the degree of blockage.

[0057] Figure 6 is a flowchart showing a method for determining the sound outlet condition of a hearing device.

[0058] Figure 7 is a schematic diagram of a hearing device. DETAILED DESCRIPTION

[0059] Various embodiments are described below with reference to the accompanying drawings. The same reference numerals always denote the same elements. Therefore, the same elements will not be described in detail for each drawing. It should also be noted that the drawings are only intended to facilitate the description of the embodiments. They are not intended as an exhaustive description of the claimed invention or a limitation on the scope of the claimed invention. In addition, the illustrated embodiments do not necessarily have all the aspects or advantages shown. Aspects or advantages described in connection with a particular embodiment are not necessarily limited to that embodiment and may be practiced in any other embodiment, even if not so illustrated or not so explicitly described.

[0060] Figure 1 is a graph showing the electrical input impedance (input Z E ) measured in Ω (ohms) as a function of frequency measured in Hz for seven different degrees of blockage of the sound outlet of a hearing device (i.e., the sound outlet of an electroacoustic transducer (also called a receiver or speaker that conducts sound outside the hearing device)). The input impedance is the electrical input impedance of the measured hearing device sensor, more specifically the electrical input impedance measured between two input terminals. The underlying effect that causes the input impedance to respond differently to different degrees of blockage is that the blockage creates acoustic and mechanical loads that are transmitted to the electrical domain via the electromagnetic circuit formed by the hearing device. The different degrees of blockage represented in the graph are as follows:

[0061] Unblocked: No earwax

[0062] cl L05: 50% blockage

[0063] cl L08: 80% blockage

[0064] cl L09: 90% blockage

[0065] cl L095 95% blockage

[0066] cl L1: 100% blockage

[0067] cl L15: 150% blockage

[0068] cl L2: 200% blockage

[0069] The latter two cases represent complete blockage of the ear canal opening, with an additional layer of earwax added thereon, providing an additional 50% blockage and an additional 100% blockage respectively.

[0070] From Figure 1 the figure shown, it can be seen that there is a relationship between the input impedance (input Z E ) and the degree of blockage. The input impedance also depends on the frequency. In other words, for different degrees of blockage, the measured input impedance depends on the frequency in different ways. As will be further elaborated below, by making use of these relationships, it is possible to efficiently detect blockage and other undesired conditions of a hearing device by measuring the input impedance, or by measuring a proportional characteristic (e.g., voltage) and processing these measurements.

[0071] As Figure 1 shown, different degrees of blockage do not produce the input impedance in the same way across the entire frequency spectrum. In this example, up to 1000 Hz, different degrees of blockage produce more or less the same input impedance. The same is true for frequencies above approximately 6000 Hz. In the frequency range between this lower limit frequency and the upper limit frequency, different degrees of blockage produce different input impedances. As a result, by measuring a first input impedance at a first frequency f1 (here, taking 2180 Hz as an example) and a second input impedance at a second frequency f2 (here, taking 3160 Hz as an example), the degree of blockage can be determined or at least estimated based on the first input impedance and the second input impedance.

[0072] For example, when the first input impedance is approximately 4 ohms higher than the second input impedance, it indicates that the degree of blockage is open, i.e., there is no earwax. In this example, when the degree of blockage is 50% (cl L05), the second input impedance is also higher than the first input impedance, although to a lesser extent. For a degree of blockage of 80% (cl L08), the first input impedance is also greater than the second input impedance, but to a smaller extent, with a difference of approximately 2 ohms. For a degree of blockage of 90% (cl L09), the first input impedance is also greater than the second input impedance, but to a very small extent, and the two input impedances are almost the same.

[0073] For a degree of blockage of 95% (cl L095), the situation changes. Instead of the first input impedance being greater than the second input impedance as in the cases of open blockage, cl L05, cl L08, and cl L09, now the second input impedance is greater than the first input impedance. The same is true for a degree of blockage of 100% (cl L1), a degree of blockage of 150% (cl L15), and a degree of blockage of 200% (cl L2). As shown in the figure, the greater the blockage, the greater the difference between the second input impedance and the first input impedance.

[0074] In Figure 2 the difference between the absolute value of the input impedance at the second frequency f2 and the absolute value of the input impedance at the first frequency f1 is plotted against the degree of blockage. Similar to Figure 1 in Figure 2 's figure, it can be seen that by using the input impedances at two selected frequencies, the degree of blockage of the hearing device can be determined. Since Figure 2 the difference shown in

[0075] increases with the degree of blockage, this difference is likely to evolve over time (since earwax blockage usually increases over time and generally does not decrease without any active measures). Therefore, by measuring the difference over time, more reliable blockage detection can be achieved. The advantage of this method is that when it is already found that the hearing device is partially blocked, an early indication can be sent from the hearing device to a mobile phone or other device connected to the hearing device, so that earwax removal or earwax filter replacement can be performed before the performance of the hearing device is significantly reduced. E a property (e.g., voltage) proportional to the impedance Z E is preferably measured for practical reasons, rather than the impedance Z g itself. Consider the output resistance R g of the generator connected to the receiver. g The resistance R E is preferably very small but not zero. The resistance R

[0076]

[0077] wherein, V spk is the voltage measured across the receiver, and V g is the measured generator voltage. In other words, Z E is proportional to V spk / V g . This proportionality is sufficient to determine changes in the impedance Z E . When V g is constant, V spk will vary with any change in the impedance Z E , and this voltage can be measured in a simple and convenient manner as follows.

[0078] There are a variety of different ways to put the above principle into practice. One way is to use white noise, that is, a signal having the same intensity at different frequencies. As Figure 3A shown, the signal can be a 0.5 - second white - noise burst. In the example shown, a period of 70 thousand samples is shown, corresponding to 1.6 seconds at a 44.1 kHz sampling rate. At approximately 16 thousand samples, the noise burst starts, and at approximately 38 thousand samples, the noise burst stops again. The average amplitude of the noise burst is ±0.2 of the signed - digit full - scale level from - 1 to +1, so the noise burst lasts a total of 20608 samples.

[0079] Continuing with this example, based on the signal shown in Figure 3A , the measured average input impedance of a receiver with an open - ended tube is shown in Figure 3B . The input impedance is measured in the frequency domain between 300 Hz and 20 kHz. The measurement is performed by a 128 - point fast Fourier transform (FFT) averaging of a 0.47 - second signal, resulting in 161 samples (20608 / 128). As with Figure 1 , for the particular receiver being tested, a local maximum is found at the first frequency f1 of 2180 Hz and a local minimum is found at the second frequency f2 of 3160 Hz. For other receivers, the frequencies f1 and f2 can be different as long as f2 > f1. In this example, the first measured electrical input impedance is 25.5 Ω and the second electrical input impedance is 22.5 Ω. Since the first input impedance is greater than the second input impedance, it can be concluded that the tube is open, i.e., there is no blockage.

[0080] As Figure 3C shown, if the signal shown in Figure 3A is used as the input when the tube portion of the hearing device is partially blocked, then in a manner similar to that referenced in Figure 3BMeasurements carried out in the same manner as described show that the input impedances at the first frequency f1 and the second frequency f2 are 24.5 Ω and 24.0 Ω, respectively. In other words, similar to Figure 2 when the first input impedance and the second input impedance are approximately the same, this may indicate a partial blockage of the tube mouth.

[0081] In addition, when the tube mouth is completely blocked, as Figure 3D shown, the second input impedance is greater than the first input impedance. In this particular example, similar measurements show that the input impedance at the first frequency f1 is 25.0 Ω and the input impedance at the second frequency f2 is 26.0 Ω.

[0082] Using white noise as described above to detect the condition of a hearing device can also be used to determine the appropriate selection of the first frequency f1 and the second frequency f2 for a particular receiver type. In other words, this white noise method can be used as part of the setup process (also known as configuration) of a hearing device. That is, different receiver types may reflect the relationship between input impedance and frequency differently. One reason for using the white noise method during setup rather than during operation (i.e., during the use of the hearing device) is that the FFT operation is accompanied by computational costs, requires more expensive components in the hearing device, and increases the power requirements of the hearing device, thus shortening the battery life and making it necessary to charge the battery more frequently in the case of using a rechargeable battery.

[0083] Instead of using white noise as the input signal (as suggested and described above with reference to Figures 3A to 3D ), the input signal (also referred to herein as the test signal) can be two successively played tones. The two tones can have the first frequency f1 and the second frequency f2, respectively, and they can each have a duration of 0.1 seconds.

[0084] Figure 4A The upper part of shows an example of the two tones presented during monitoring of the test signal at 44.1 kHz for approximately 35 thousand samples (i.e., a time period of approximately 0.8 seconds). On the y-axis, values representing the voltages measured at the two speaker terminals of the hearing device are presented. In Figure 4A the lower part, the root mean square (RMS) voltage value (referred to as RMS1) measured at the receiver input for the first tone using the first frequency f1, and the RMS voltage value (referred to as RMS2) measured for the second tone using the second frequency f2 are shown. In addition, the difference between the two is depicted, which, for clarity, is multiplied by three and thus represented as 3ΔRMS. Since the triple difference 3ΔRMS is negative, i.e., RMS1 is greater than RMS2, it can be concluded that there is no blockage, i.e., the tube mouth is clear.

[0085] Figure 4BAnother example with the same two tones is shown. During Figure 4B monitoring a test signal of approximately 35 thousand samples at the upper part of, two tones are presented, similar to the test signal shown in Figure 4A . As shown, in this example, the tones generate different voltages between the speaker terminals. Compared with the similar measurements of the example shown in Figure 4A , the voltage generated by the second frequency f2 is higher. Since it has been found that the values representing the voltage measurements at the terminals will be different for different conditions of the hearing device, conclusions about the condition of the hearing device can be drawn by measuring the voltage between the speaker terminals at the selected frequencies f1 and f2. As mentioned before, the voltage measured between the speaker terminals is proportional to the input impedance. Since the impedance is an indication of the condition of the hearing device, a computationally efficient method for monitoring this condition is to measure the voltage between the terminals at the selected frequencies (i.e., the frequencies at which the device has visible local maxima or minima in the electrical impedance).

[0086] The advantage of using the method proposed above (as shown in Figure 4A and 4B ) is that no FFT calculation is required. The frequencies f1 and f2 can be pre-calculated and stored in the memory of the hearing device. Since the frequencies f1 and f2 are specific to the receiver model, the frequency values can be stored when selecting a specific receiver for a specific hearing device, for example. One method of calculating these frequencies is to use the method described above (as shown in Figures 3A - 3D ). By avoiding FFT calculations in the hearing device itself, less computational power is required during use (i.e., during the operation of the hearing device) to detect an undesired condition that affects the impedance (such as a blocked receiver nozzle).

[0087] Figure 5 is a graph showing the relationship between the difference in RMS (ΔRMS) and the degree of blockage. In the example shown, additional artificial earwax was added after each measurement.

[0088] As shown, just as the impedance difference calculated from the input impedance based on the two frequencies f1 and f2 can be used to detect the degree of blockage, the voltage difference calculated from the voltage measurements between the two speaker terminals at the two frequencies f1 and f2 can be used to determine the degree of blockage. As shown, in addition to determining the degree of blockage of the nozzle, by using this method, it is also possible to detect, for example, the absence of an earwax filter, i.e., a micro-device installed at the nozzle to prevent earwax from entering the hearing device. In addition, it is also possible to detect a blocked earwax filter.

[0089] Although not described, the principle of detecting an undesired condition of the hearing device by measuring the voltage between the receiver terminals (utilizing the fact that the voltage is proportional to the impedance at two or more selected frequencies) can also be used to detect, for example, leakage coupling.

[0090] Figure 6 is a flow chart showing a method 600 for monitoring the condition of the sound tube of a hearing device, also known as a receiver clogging test routine. The test routine can be advantageously performed each time the hearing device is turned on, before assuming normal operation of the hearing device. After starting (601), a first sine tone is played for 0.1 seconds (602). The first tone can be generated by an internal generator. As in the above example, the first sine tone can have a first frequency f1, as described previously. Next, the voltage between the two speaker terminals is measured and the measured RMS voltage is stored in the memory (603). Thereafter, a second tone is played for 0.1 seconds (604). This tone can have a second frequency f2 and can also be generated by an internal generator. The voltage between the terminals caused by the second tone is measured between the speaker terminals, and the measured RMS voltage is stored in the memory (605). Based on the two RMS voltage values associated with the first tone and the second tone respectively, the difference ΔRMS is calculated (606).

[0091] In the case where the difference is below the missing cerumen (earwax) filter limit LMF (607), the state of the hearing device is set to filter missing (608). In the case of entering this state, this can in turn trigger sending an indication to a mobile phone or other device linked to the hearing device. In Figure 5 the example, the LMF limit can be -25 mV.

[0092] In the case where the difference is below the clear receiver sound tube limit LO (609) (and above the LMF limit), the state of the hearing device is set to receiver sound tube clear (610). In Figure 5 the example, the LO limit can be -17 mV.

[0093] In the case where the difference is below the receiver sound tube clogging limit LC (611) (and above the LO limit), the state of the hearing device can be set to receiver sound tube partially clogged (612). In Figure 5 the example, the LC limit can be 0 mV.

[0094] In the case where the difference is below the earwax filter blockage limit (613) (and above the LC limit), the state of the hearing device can be set to receiver sound tube completely blocked (614).

[0095] Finally, in the case where the difference is above the earwax filter blockage limit CB, the state of the hearing device can be set to earwax filter blocked (615). In Figure 5 the example, the CB limit can be +10 mV.

[0096] When the state of the hearing device is determined by the relationship of the measured ΔRMS to various limits provided in the structure, the current state is passed to a suitable interface in the hearing device, after which the hearing device is in place for normal operation (616) in an exit step (to normal HI (hearing instrument) operation). The possible states of the hearing device derived from the measurement, namely filter missing, receiver nozzle unobstructed, receiver nozzle partially blocked, receiver nozzle completely blocked, and earwax filter blocked, can usefully alert the user of the hearing device whether the receiver of the hearing device is unobstructed, blocked, missing an earwax filter, or in need of an earwax filter replacement.

[0097] Figure 7 The hearing device 700 is generally shown by way of example. As shown, the microphone 701 can capture sound waves. Even though only a single microphone is shown, multiple microphones may be available. Additionally, the microphone can be arranged to capture sounds to be used, such as for compensating for noise present in the surrounding environment, in addition to capturing sounds to be presented to the user of the hearing device. The microphone 701 can be communicatively connected to the input signal processor 702.

[0098] A transceiver module 703 equipped with an antenna 704 is provided for wirelessly receiving data from, for example, another hearing device and / or an external device (e.g., a mobile phone). The transceiver module 703 and the input signal processor 702 can be connected to a controller 705, which is configured to control the signals captured via the microphone 701 and processed by the input signal processor 702, as well as the signals received via the antenna 704. The processed audio data can be transferred from the input signal processor 702 to the output module 706, which includes an output amplifier 707 and an oscillator 708. As shown, the input signal processor 702 is arranged to: transfer the audio data directly to the output amplifier 707. Via an internal resistor 709, the signal (sometimes referred to as data) can be transferred from the output amplifier 707 to the receiver 711 (also referred to herein as an electroacoustic transducer, transducer, or speaker). As shown, a voltage measuring device 710 is arranged between the two input terminals of the receiver 711. By using the voltage measuring device 710, the RMS voltage between the terminals of the receiver 711 can be measured, and this RMS voltage can be used to determine the condition of the hearing device, as described above. The voltage measuring device 710 can be connected to the controller 705 such that the measurements made can be processed to determine or at least estimate the condition of the hearing device. Even though not shown, the receiver nozzle can connect the receiver 711 to the outside of the hearing device 700.

[0099] In this way, the current condition of the receiver nozzle of the hearing device can be monitored quickly, safely, and reliably and communicated to the user of the hearing device.

[0100] Although specific features have been shown and described, it is to be understood that they are not intended to limit the claimed invention, and those skilled in the art will appreciate that various changes and modifications can be made without departing from the scope of the claimed invention. Accordingly, the specification and drawings are to be regarded as illustrative rather than restrictive. The claimed invention is intended to cover all alternatives, modifications, and equivalents.

[0101] List of Reference Numerals

[0102] 600 – Method for Monitoring the Condition of the Tubular Opening of the Receiver / Receiver Blockage Test Routine

[0103] 601 – Start

[0104] 602 – Play the First Sine Tone

[0105] 603 – Measure RMS1

[0106] 604 – Play the Second Sine Tone

[0107] 605 – Measure RMS2

[0108] 606 – Calculate ΔRMS

[0109] 607 – ΔRMS < LMF?

[0110] 608 – Filter Missing

[0111] 609 – ΔRMS < LO?

[0112] 610 – Receiver Tubular Opening Clear

[0113] 611 – ΔRMS < LC?

[0114] 612 – Receiver Tubular Opening Partially Blocked

[0115] 613 – ΔRMS < CB?

[0116] 614 – Receiver Tubular Opening Completely Blocked

[0117] 615 – Earwax Filter Blocked

[0118] 616 – To Normal HI Operation

[0119] 700 – Hearing Device

[0120] 701 – Microphone

[0121] 702 – Input Signal Processor

[0122] 703 – Transceiver Module

[0123] 704 – Antenna

[0124] 705 - Controller

[0125] 706 - Output Module

[0126] 707 - Output Amplifier

[0127] 708 - Oscillator

[0128] 709 - Internal Resistance

[0129] 710 - Voltage Measuring Device

[0130] 711 - Receiver / Electroacoustic Transducer / Speaker

Claims

1. A computer-implemented method for detecting a condition of a hearing device (700), the hearing device comprising an electroacoustic transducer (711) having at least two input terminals, a nozzle connected to the transducer (711) and a controller (705), the method comprising: generating an electrical signal for reproduction by the transducer (711); estimating a first voltage (RMS1) at a first frequency (f1) between input terminals of the transducer by applying the electrical signal to the transducer; estimating a second voltage (RMS2) at a second frequency (f2) by applying the electrical signal, wherein the second frequency is higher than the first frequency; determining, by the controller (705), a difference (ΔRMS) between the first voltage and the second voltage; assigning a first state to the condition if the difference is below a first threshold; assigning a second state to the condition if the difference is above a second threshold, wherein the second threshold is higher than the first threshold; and assigning a third state to the condition if the difference is between the first threshold and the second threshold, Wherein, the first state is that the pipe opening is unobstructed, the second state is that the pipe opening is completely blocked, and the third state is that the pipe opening is partially blocked.

2. The method according to claim 1, wherein: The hearing device (700) is a receiver-in-ear (RIE) hearing device.

3. A method according to any one of the preceding claims, wherein: The first voltage and the second voltage reflect a first electrical input impedance and a second electrical input impedance, respectively.

4. A method according to any one of the preceding claims, wherein: The electroacoustic transducer (711) is a balanced armature transducer.

5. A method according to any one of the preceding claims, wherein: The frequencies are audio frequencies, wherein the first frequency (f1) is lower than 2500 Hz and the second frequency (f2) is higher than 2500 Hz.

6. A method according to any one of the preceding claims, wherein: The first frequency and the second frequency (f1, f2) are selected based on a location where the transducer (711) has a significant electrical input impedance resonance.

7. A method according to any one of the preceding claims, wherein: The electrical signal is a preset audio signal stored in a memory included in the hearing device (700).

8. A method according to any one of the preceding claims, wherein: The nozzle of the transducer is provided with a filter for preventing earwax from transferring into the nozzle, and the method further comprises: A fourth state is assigned to the situation if the difference is below a third threshold value, wherein the third threshold value is below the first threshold value.

9. The method according to claim 8, wherein: The hearing device (700) is arranged to communicate with an external device such as a mobile phone, the method further comprising: If the first state is assigned to the condition, sending a "canal vent clear" notification signal from the hearing device (700) to the external device; If the second state is assigned to the condition, sending a "blocked orifice" notification signal from the hearing device to the external device; If the third state is assigned to the condition, sending a "partially blocked orifice" notification signal from the hearing device to the external device; and If the fourth state is assigned to the situation, a “filter missing” notification signal is sent from the hearing device to the external device.

10. A hearing device (700) comprising an electroacoustic transducer (711) having at least two input terminals, a nozzle connected to the transducer (711), and a controller (705), the controller (705) being configured to: generating an electrical signal for reproduction by the transducer; estimating a first voltage (RMS1) at a first frequency (f1) between input terminals of the electroacoustic transducer in the hearing device (700) by applying the electrical signal; A second voltage (RMS2) at a second frequency (f2) in the hearing device (700) is estimated by applying the electrical signal between input terminals of the electroacoustic transducer, wherein: The second frequency is higher than the first frequency; determining a difference (ΔRMS) between the first voltage and the second voltage; assigning a first state to the condition if the difference is below a first threshold; assigning a second state to the condition if the difference is above a second threshold, wherein the second threshold is higher than the first threshold; and assigning a third state to the condition if the difference is between the first threshold and the second threshold, Wherein, the first state is that the pipe opening is unobstructed, the second state is that the pipe opening is completely blocked, and the third state is that the pipe opening is partially blocked.

11. The hearing device according to claim 12, wherein: The hearing device is a receiver-in-ear (RIE) hearing device.

12. The hearing device according to claim 10 or 11, wherein: The electroacoustic transducer is a balanced armature transducer.

13. The hearing device according to any one of claims 10 to 12, wherein: The electrical signal is a preset audio signal stored in a memory.

14. A system comprising a hearing device (700) according to claims 10 to 13 and an external device, wherein: The hearing device is arranged to communicate the status of the condition to the external device.

15. A computer program product comprising instructions which, when executed by the controller (705), cause it to perform the method according to any one of claims 1 to 9.

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