Hearing device for performing real ear measurements, and method of its operation

Abstract

The disclosure relates to a hearing device configured to be at least partially inserted into an ear canal of a user, the hearing device comprising a processing unit (115) for audio signal processing of an input audio signal (A, B) to obtain an output audio signal (O), wherein, in a first operational mode for compensating for a hearing loss of the user, the audio signal processing comprises amplifying, in an amplification operation, the input audio signal (A, B) according to a transfer function. The disclosure also relates to a method of operating the hearing device. To provide for an improved real ear measurement (REM) system, e.g., with regard to an accessibility and / or a useability of the measurement equipment, the disclosure proposes that, in a second operational mode for providing a stimulus for performing the real ear measurement (REM), the processing unit (115) is configured to perform the audio signal processing by processing a radio audio signal (B) received from a remote audio source via radio frequency (RF) radiation as the input audio signal, wherein the audio signal processing comprises the amplification operation.

Description

TECHNICAL FIELD

[0001] The disclosure relates to a hearing device configured to be worn at an ear of a user, according to the preamble of claim 1. The disclosure further relates to a to a method of operating a hearing device, according to the preamble of claim 15.BACKGROUND

[0002] Hearing devices may be used to improve the hearing capability or communication capability of a user, for instance by compensating a hearing loss of a hearing-impaired user, in which case the hearing device is commonly referred to as a hearing instrument such as a hearing aid, or hearing prosthesis. A hearing device may also be used to output sound based on an audio signal which may be communicated by a wire or wirelessly to the hearing device. A hearing device may also be used to reproduce a sound in a user's ear canal detected by an input transducer such as a microphone or a microphone array. The reproduced sound may be amplified to account for a hearing loss, such as in a hearing instrument, or may be output without accounting for a hearing loss, for instance to provide for a faithful reproduction of detected ambient sound and / or to add audio features of an augmented reality in the reproduced ambient sound, such as in a hearable. A hearing device may also provide for a situational enhancement of an acoustic scene, e.g. beamforming and / or active noise cancelling (ANC), with or without amplification of the reproduced sound. A hearing device may also be implemented as a hearing protection device, such as an earplug, configured to protect the user's hearing. Different types of hearing devices configured to be be worn at an ear include earbuds, earphones, hearables, and hearing instruments such as receiver-in-the-canal (RIC) hearing aids, behind-the-ear (BTE) hearing aids, in-the-ear (ITE) hearing aids, invisible-in-the-canal (IIC) hearing aids, completely-in-the-canal (CIC) hearing aids, cochlear implant systems configured to provide electrical stimulation representative of audio content to a user, a bimodal hearing system configured to provide both amplification and electrical stimulation representative of audio content to a user, or any other suitable hearing prostheses. A hearing system comprising two hearing devices configured to be worn at different ears of the user is sometimes also referred to as a binaural hearing device. A hearing system may also comprise a hearing device, e.g., a single monaural hearing device or a binaural hearing device, and a user device, e.g., a smartphone and / or a smartwatch, communicatively coupled to the hearing device.

[0003] Hearing devices are often employed in conjunction with communication devices, such as smartphones or tablets, for instance when listening to sound data processed by the communication device and / or during a phone conversation operated by the communication device. More recently, communication devices have been integrated with hearing devices such that the hearing devices at least partially comprise the functionality of those communication devices. A hearing system may comprise, for instance, a hearing device and a communication device.

[0004] The field of hearing loss compensation has evolved significantly over the years, with a primary focus on developing accurate personalized adjustments for hearing instruments that can consistently benefit a broad population. However, despite these advancements, there are still limitations because of individual differences in hearing loss, ear anatomy, and acoustics which in turn influence the actual output of the hearing instrument. Providing generally applicable adjustments for the hearing loss compensation is further complicated because it is difficult to identify which subjects can be considered typical. Consequently, a generally estimated personalized adjustment cannot be applied for a consistent benefit. This has led to the need for a more precise methodology that can accurately measure the output of hearing instruments inside an individual's ear canal based on which the hearing instrument adjustments can be fitted to the individual.

[0005] Currently, real ear measurements (REMs) are considered best practice for fitting hearing instruments. REM systems involve using specialized hardware and software to measure the actual output of hearing instruments inside an individual's ear canal. The REM probe, which consists of a reference microphone and a probe microphone with a disposable probe tube which is inserted into the ear canal to measure the sound delivered by the hearing instrument inside the ear canal, at a close distance to the tympanic membrane. The REM system uses the signal from the reference microphone to regulate the sound level of an acoustical stimulus at a reference point, e.g., just above or below the ear at which the microphone of the hearing instrument is located, enabling the REM system to present a calibrated stimulus. When using the probe microphone to measure a sound pressure level (SPL) of the stimulus near the tympanic membrane, the conducted measurements include the impact of the individual differences mentioned above. REMs can thus display the actual output of the hearing instrument in the individual ear canal and the hearing instrument can be programmed to deliver a verified output in the individuals' ear canal as opposed to relying on a non-verified predicted output based on average parameters.

[0006] Despite those benefits of hearing instrument fitting based on REMs, there are several limitations to the current state of the art. At first, REM equipment is costly, which can limit the availability and uptake of REM systems. Secondly, REM equipment requires specially trained personnel to understand and manage measurement procedures and make clinical decisions based on them. In particular, managing the insertion of the probe tube into the ear canal can be challenging even for hearing care professionals (HCPs) having acquired such a training or expertise. Thirdly, measurements involving low levels of the stimulus presented to the individual require low ambient noise levels to obtain valid measurement results, demanding a quiet measurement environment for conducting REMs. Finally, current REM systems are not suitable for also allowing a remote fitting of the hearing instrument, i.e., at a location different from the location of the HCP, due to a lack of availability of an REM system to the user of the hearing instrument and the requirement of an REM system being operated by an HCP or equally trained staff.SUMMARY

[0007] It is an object of the present disclosure to provide for an improvement of current REM systems with regard to at least one of the above mentioned shortcomings, in particular with regard to one or more of an accessibility, a complexity, an affordability, an accuracy, and a useability of the measurement equipment and / or with regard to the demands on the environment and / or the personnel required for operating the equipment. It is another object to propose a hearing device and / or a method for its operation that allows to accurately measure the output of the hearing device inside an individual ear canal, e.g., by also reducing a need for additional and / or costly and / or specialized equipment. It is a further object to provide for an easy-to-use REM equipment which may not only be operated by trained professionals or equally capable individuals but also by less qualified personnel such as, for instance, a user of the hearing instrument or a significant other of the user. It is another object to enable or facilitate a remote fitting of the hearing device and / or a self-fitting of the hearing device, e.g., by a user of the hearing device or a significant other, by means of REMs. It is a further object to improve an accessibility to REM systems to a broader population, which may ultimately lead to more accurate personalized adjustments and an increased acceptance of hearing devices.

[0008] At least one of these objects can be achieved by a hearing device comprising the features of patent claim 1 and / or a method of operating a hearing device comprising the features of patent claim 15. Advantageous embodiments are defined by the dependent claims and the following description.

[0009] Accordingly, the present disclosure proposes a hearing device configured to be at least partially inserted into an ear canal of a user, the hearing device comprising an audio input unit for obtaining an input audio signal, the audio input unit comprising a radio receiver configured to receive a radio audio signal from a remote audio source via radio frequency (RF) radiation; a processing unit for audio signal processing of the input audio signal to obtain an output audio signal; and an audio output unit for outputting sound based on the output audio signal, wherein, in a first operational mode for providing the outputted sound so as to compensate for a hearing loss of the user, the audio signal processing comprises amplifying, in an amplification operation, the input audio signal (A, B) according to a transfer function, and, in a second operational mode for providing the outputted sound as a stimulus for performing a real ear measurement (REM), the processing unit is configured to perform the audio signal processing by processing the radio audio signal as the input audio signal, wherein the audio signal processing comprises said amplification operation.

[0010] Thus, by providing for a second operational mode of the hearing device, in which the hearing device is enabled to employ a radio audio signal received from a remote audio source for producing a stimulus for the REM, the exigencies for an additional equipment, which may be required for performing the REM, can be effectively reduced and / or an operability of the REM system can be facilitated, e.g., with regard to the measuring environment and / or the personnel for performing the REM. For example, the demands on a sound source for providing a suitable stimulus of current REM systems, such as a calibrated and / or high quality external loudspeaker system, can be lowered. As another example, a tedious handling of the probing equipment of current REM systems, such as a probe microphone attached to a probe tube and / or a reference microphone, may be facilitated or avoided. As a further example, REMs may thus not be restricted to be performed in surroundings in which a noise level is low, so as to allow measurements with a stimulus of a low level, and / or which are distant or acoustically isolated from neighboring people sensitive to noise, so as to allow measurements with a stimulus of a high level. As another example, an ease-of-use to perform REMs can be increased, e.g., with regard to allowing a user of the hearing instrument or a significant other to initiate at least part of the steps of performing the REM, e.g., at a location remote from a trained personnel and / or without further assistance by a trained personnel. As a result, an accessibility of REM systems for users of a hearing device and / or for personnel performing REMs, e.g., with or without a specialized training, can be increased, and / or REMs may be performed more frequently in a broad population.

[0011] Independently, the present disclosure proposes a hearing system for performing an REM comprising the hearing device, and the remote audio source. In some implementations, the hearing system may further comprise an external sound source, e.g., a loudspeaker, configured to emit sound in an environment of the user.

[0012] Independently, the present disclosure proposes a method of operating a hearing device configured to be at least partially inserted into an ear canal of a user, the hearing device comprising an audio input unit for obtaining an input audio signal, the audio input unit comprising a radio receiver configured to receive a radio audio signal from a remote audio source via radio frequency (RF) radiation; a processing unit; and an audio output unit for outputting sound based on the output audio signal, the method comprising performing, by the processing unit, an audio signal processing of the input audio signal to obtain an output audio signal, wherein, in a first operational mode for providing the outputted sound so as to compensate for a hearing loss of the user, the audio signal processing comprises amplifying, in an amplification operation, the input audio signal according to a transfer function, and, in a second operational mode for providing the outputted sound as a stimulus for performing a REM, the audio signal processing is performed by processing the radio audio signal as the input audio signal, wherein the audio signal processing comprises said amplification operation.

[0013] Independently, the present disclosure also proposes a non-transitory computer-readable medium storing instructions that, when executed by a processor, which may be included in a hearing device, cause a hearing device to perform operations of the method.

[0014] Subsequently, additional features of some implementations of the hearing device and / or the hearing system and / or the method of operating a hearing device and / or the computer readable medium are described. Each of those features can be provided solely or in combination with at least another feature. The features can be correspondingly provided in some implementations of the hearing device and / or the hearing system and / or the method and / or the computer readable medium.

[0015] In some implementations, the audio input unit further comprises a sound detector configured to detect sound in an ambient environment of the user and to provide an ambient audio signal representative of the detected sound, wherein, in the first operational mode, the processing unit is configured to perform the audio signal processing by processing the ambient audio signal and / or the radio audio signal as the input audio signal. In some implementations, the input audio signal comprises the radio audio signal and / or the ambient audio signal. In some examples, in the first operational mode, the processing unit is configured to perform the audio signal processing of the input audio signal by processing the ambient audio signal or by processing the radio audio signal or by processing the ambient audio signal and the radio audio signal. In some examples, in the second operational mode, the processing unit is configured to perform the audio signal processing of the input audio signal by processing the radio audio signal or by processing the ambient audio signal.

[0016] In some implementations, the processing unit is configured, when operating in the second operational mode, to perform the audio signal processing so as to provide for different stimuli comprising a first stimulus, for which the audio signal processing is performed by processing the radio audio signal as the input audio signal, and a second stimulus, for which the audio signal processing is performed by processing the ambient audio signal as the input audio signal. In some implementations, the processing unit is configured, when operating in the second operational mode, to initiate the outputting of the different stimuli by the audio output unit at a different time, e.g., in a temporal sequence.

[0017] In some implementations, in the second operational mode, the audio signal processing comprises, in addition to the amplification operation, modifying, in a stimulus preparation operation, a property of the input audio signal so as to provide for a modified input audio signal adapted for conditions required for the real ear measurement (REM). In some implementations, the property of the input audio signal comprises one or more of a sound pressure level (SPL) represented by the input audio signal; a range and / or shape of a frequency spectrum included in the input audio signal; and a vocal effort represented by the input audio signal.

[0018] In some implementations, the processing unit is configured to execute the stimulus preparation operation before the amplification operation. In some examples, the processing of the input audio signal comprises modifying the property of the input audio signal so as to provide for the modified input audio signal adapted for conditions required for the real ear measurement (REM); and amplifying the modified audio signal according to the transfer function. In some implementations, the processing unit is configured to execute the stimulus preparation operation after the amplification operation.

[0019] In some implementations, the processing unit is configured, during said modifying of the property of the input audio signal, to provide for a different SPL represented by the modified input audio signal when providing the first stimulus as compared to when providing the second stimulus. In some implementations, the processing unit is configured, during said modifying of the property of the input audio signal, to provide for a lower SPL represented by the modified input audio signal when providing the first stimulus as compared to when providing the second stimulus.

[0020] In some implementations, the different stimuli comprise a third stimulus and, during said modifying of the property of the input audio signal, the processing unit is configured to provide for a higher SPL represented by the modified input audio signal when providing the third stimulus as compared to when providing the first and second stimulus. In some implementations, when providing the third stimulus, the audio signal processing is performed by processing the radio audio signal as the input audio signal.

[0021] In some implementations, when providing the first stimulus, the SPL represented by the modified audio signal is at most 60 dB, e.g., at most 55 dB. In some implementations, when providing the second stimulus, the SPL represented by the modified audio signal is between 50 dB and 80 dB, e.g., between 60 dB and 70 dB. In some implementations, when providing the third stimulus, the SPL represented by the modified audio signal is at least 70 dB, e.g., at least 75 dB.

[0022] In some implementations, the SPL represented by the audio signal, e.g., the input audio signal and / or the modified input audio signal, may be representative of an SPL of a sound field which would be produced by an external sound source outside of the ear. For example, the SPL represented by the audio signal may be equivalent to an SPL of sound produced by the external sound source, e.g., a loudspeaker, as a stimulus for REM, e.g., when measured in the environment of the user. For instance, the SPL may be measurable at the position of the external sound source and / or at the position of the hearing device, e.g., by the sound detector included in the hearing device. For instance, the SPL represented by the audio signal may be representative of an SPL of a sound field produced by the external sound source when sound is produced by the external sound source based on the audio signal.

[0023] In some implementations, the processing unit is configured to switch between the first operational mode and the second operational mode depending on a control signal. In some instances, the processing unit is configured to receive the control signal from a user interface, e.g., depending on an input of the user on the user interface. In some examples, the user interface is included in the hearing device and / or in a computing device communicatively coupled with the hearing device. In some examples, the processing unit is configured to receive the control signal from a radio receiver included in the hearing device, wherein the radio receiver is configured to obtain the control signal via RF radiation, e.g., from the computing device.

[0024] In some implementations, the processing unit is configured, in a calibration operation for calibrating the stimulus provided in the second operational mode, to compare the ambient audio signal to a reference quantity indicative of one or more properties of the ambient audio signal required for providing the stimulus; and to adjust, based on the comparison, one or more processing parameters applied in said stimulus preparation operation when processing the ambient audio signal as the input audio signal. In some implementations, the processing unit is configured to receive the reference quantity from a radio receiver included in the hearing device, wherein the radio receiver is configured to obtain the reference quantity via RF radiation, e.g., from a computing device. In some examples, the reference quantity may be an audio signal received by the radio receiver. E.g., the reference quantity may be an audio signal representative of a sound with one or more properties required for the stimulus.

[0025] In some implementations, the hearing device further comprises an ear-canal microphone configured to provide an in-the-ear audio signal indicative of a sound detected inside the ear canal. In some implementations, in the second operational mode, the processing unit is configured to evaluate the in-the-ear audio signal so as to obtain an output data signal indicative of at least one parameter determined in the REM. In some implementations, the hearing device comprises a radio transceiver configured to transmit the output data signal to a computing device via RF radiation. In some implementations, the radio receiver for receiving the radio audio signal is comprised in the radio transceiver for transmitting the output data signal. E.g., the radio receiver and the radio transceiver may be implemented as a single unit.

[0026] In some implementations, the radio receiver is configured to receive the radio audio signal via a Bluetooth protocol. In some implementations, the radio transceiver is configured to transmit the output data signal via a Bluetooth protocol.

[0027] In some implementations, the hearing device further comprises a probe tube attachable to the ear-canal microphone. In some implementations, when evaluating the in-the-ear audio signal, the processing unit is configured to obtain calibration data based on the in-the-ear audio signal when the probe tube is attached to the ear-canal microphone. In some instances, the processing unit is further configured to calibrate the in-the-ear audio signal when the probe tube is removed from the ear-canal microphone based on the calibration data. In some examples, the processing unit is configured to store the calibration data in a memory and / or to retrieve the calibration data when evaluating the in-the-ear audio signal.

[0028] In some implementations, the hearing system comprises an external sound source, e.g., a loudspeaker, configured to provide for the sound detected by the sound detector of the hearing device. In some implementations, the hearing system comprises the remote audio source configured for data transmission of the radio audio signal to the radio receiver of the hearing device. E.g., the remote audio source may be implemented as a user device such as a portable device and / or a computing device.BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings. The drawings illustrate various embodiments and are a part of the specification. The illustrated embodiments are merely examples and do not limit the scope of the disclosure. Throughout the drawings, identical or similar reference numbers designate identical or similar elements. In the drawings: Fig. 1schematically illustrates a common system for performing a real ear measurement (REM); Fig. 2schematically illustrates an REM probe of the system illustrated in Fig. 1; Fig. 3schematically illustrates an exemplary hearing device; Fig. 4schematically illustrates the hearing device illustrated in Fig. 3 in a first operational mode; Figs. 5 - 7schematically illustrate the hearing device illustrated in Fig. 3 in a second operational mode; and Figs. 8, 9schematically illustrate the hearing device illustrated in Fig. 3 in a calibration operation; Figs. 10- 12schematically illustrate an exemplary hearing device in an REM evaluation operation; Fig. 13schematically illustrate an exemplary hearing device implemented as a receiver-in-the-canal (RIC) hearing device; Figs. 14, 15schematically illustrate a system for performing an REM; and Figs. 16 - 19schematically illustrate some exemplary methods of operating a hearing device and / or a hearing system according to principles described herein. DETAILED DESCRIPTION OF THE DRAWINGS

[0030] FIG. 1 illustrates a system 11 for performing real ear measurements (REMs). REM system 11 is known in the art as a tool for audiologists, health care professionals (HCP), and the like to adjust, e.g., to program, and / or verify an amplification produced by hearing instruments when inserted into an ear canal of a user to compensate for an individual hearing loss. REM system 11 is described here for the purpose to illustrate some differences and / or advantages of new hearing devices, REM systems, and methods of operating a hearing device and / or performing an REM encompassed in this disclosure, as further described below. In some embodiments, the devices, systems, and method described below may also include one or more of the features of REM system 11 and / or the method of its operation.

[0031] As illustrated, REM system 11 comprises a probe 12, a loudspeaker system 17, a hardware unit 18, and a computer system 19. Computer system 19, e.g., a personal computer, comprises a processor for executing instructions, e.g., one or more computer programs installed on a transitory and / or non-transitory computer-readable medium, for performing an REM and / or for a fitting of a hearing instrument. The at least one computer program, e.g., a software installed on computer system 19, represents a man-machine interface of REM system 11 and may be operated by an expert or a specially trained person, e.g., an HCP.

[0032] REM hardware unit 18 comprises an interface for connecting to computer system 19. Hardware unit 18 is further connected to probe 12 and loudspeaker system 17. E.g., hardware unit 18 can comprise one or more amplifiers to drive loudspeaker 17 and / or additional processing circuitry. Loudspeaker system 17 is configured to present a calibrated sound field 24 as a stimulus for a test subject 22 wearing a hearing instrument 23 in the room where subject 22 is sitting. Due to the requirement of reliably providing stimulus 24 in a calibrated and / or reproducible manner, loudspeaker system 17 is of a high quality and specific design, which is reflected in an elevated purchase price.

[0033] FIG. 2 illustrates REM probe 12 in further detail. REM probe 12 comprises an ear canal probe 13 and a reference microphone 14. Ear canal probe 13 comprises a probe microphone and a disposable probe tube, which is mounted to the probe microphone. The probe tube is insertable into an ear canal 26 of the ear 25 at which subject 22 is wearing hearing instrument 23 to measure the sound inside ear canal 26. To this end, as illustrated, the probe tube may be inserted into ear canal 26 in a way that it passes through a part 24 of hearing instrument 23 also inserted into ear canal 26, which may also be referred to as an ITE part. To illustrate, ITE part 24 may comprise, e.g., a receiver for outputting sound and / or a sealing for providing acoustic isolation of an inner region of ear canal 26, which may be positioned at a larger distance from a tympanic membrane 27 inside ear canal 26 than the probe tube. For example, the probe tube may be positioned at distance of 5 mm or less from tympanic membrane 27 in a way that minimizes reflections or reverberations that could affect the measurement. Further, a sound pressure level (SPL) measurable at this position is directly related to the SPL perceived by subject 22. The probe tube may be provided rather thin and soft to facilitate insertion into ear canal 26.

[0034] Reference microphone 14 serves the purpose of measuring sound field 24 provided by loudspeaker system 17 at a reference point outside ear canal 26. E.g., reference microphone 14 may be mounted just above or below ear 25 of subject 22 and / or close to a microphone of hearing instrument 23. REM system 11 can thus be configured to regulate, based on measuring an SPL of sound field 24 by reference microphone 14 at the reference point, the sound level of sound field 24 provided by loudspeaker system 17 to a required level. In this way, REM system 11 can provide for a calibrated stimulus 24. Further, REM system 11 can be configured to determine a real-ear aided gain (REAG) defined as the SPL near the eardrum, which can be measured via ear canal probe 13, minus the SPL at the reference point, which can be measured via reference microphone 14.

[0035] REM system 11 illustrated in Figs. 1 and 2 has a number of drawbacks: the REM equipment is costly which limits an accessibility and uptake of REM system 11; the REM equipment requires specially trained personnel in order to understand and manage measurement procedures and making clinical decisions from them. In particular, the training requirements for HCPs are relatively high so not all HCPs are capable of performing REMs. For instance, managing the insertion of the tube of the ear canal probe 13 represents a challenge to HCPs; measurements with low levels of stimulus 24 require low ambient noise levels in order to obtain valid measurement results limiting the choice of locations suitable to perform REMs; measurements with high levels of stimulus 24 may disturb people in proximity to the measurements further limiting the choice of locations for performing REMs; REM system 11 is not suitable for a remote fitting, i.e., a fitting during which the user of hearing instrument 23 and the HCP are at different locations, due to a lack of availability of REM system 11 to the user and the requirement of REM system 11 being operated by an HCP or equally trained staff; and for the same reasons, REM system 11 is also not suitable for a self-fitting, i.e., a fitting of hearing instrument 23 performed by the user on his own.

[0036] FIG. 3 illustrates an exemplary hearing device 111 configured to be worn at an ear of a user. Hearing device 111 may be implemented by any type of hearing device configured to enable or enhance hearing or a listening experience of a user wearing hearing device 111. For example, hearing device 111 may be implemented by a hearing aid configured to provide an amplified version of audio content to a user, a sound processor included in a bimodal hearing system configured to provide both amplification and electrical stimulation representative of audio content to a user, or any other suitable hearing instrument, or an earbud or an earphone or a hearable.

[0037] Different types of hearing device 111 can also be distinguished by the position at which they are worn at the ear. Some hearing devices, such as behind-the-ear (BTE) hearing aids and receiver-in-the-canal (RIC) hearing aids, typically comprise an earpiece configured to be at least partially inserted into an ear canal of the ear, and an additional housing configured to be worn at a wearing position outside the ear canal, in particular behind the ear of the user. Some other hearing devices, as for instance earbuds, earphones, hearables, in-the-ear (ITE) hearing aids, invisible-in-the-canal (IIC) hearing aids, and completely-in-the-canal (CIC) hearing aids, commonly comprise such an earpiece to be worn at least partially inside the ear canal without an additional housing for wearing at the different ear position.

[0038] As shown, hearing device 111 includes a processing unit 115 communicatively coupled to an audio input unit 113 and an audio output unit 119. Audio input unit 113 is configured to obtain an input audio signal. Processing unit 115 is configured to provide for a processing of the input audio signal to obtain an output audio signal. Audio output unit 119 is configured to output sound based on the output audio signal. Hearing device 111 may include additional or alternative components as may serve a particular implementation.

[0039] Audio input unit 113 comprises a radio receiver 125 configured to receive a radio audio signal from a remote audio source via radio frequency (RF) radiation. The input audio signal, which is received by processing unit 115, may then at least partially be based on the radio audio signal. Radio receiver 125 may be configured for wireless data reception of the radio audio signal. For instance, the radio audio signal may be received in accordance with a Bluetooth ™< protocol and / or by any other type of RF communication. In some examples, the remote audio source may be a remote microphone, e.g., a table microphone or a clip-on microphone, configured to detect sound at a remote location and transmit the radio audio signal indicative of the detected sound to radio receiver 125. In some examples, the remote audio source may be a streaming source configured for streaming the radio audio signal to radio receiver 125. In some examples, the remote audio source may be a user device, e.g., a portable device such as a smartphone, tablet, smartwatch and / or the like, or a computing device such as a personal computer, configured for data transmission of the radio audio signal to radio receiver 125. In some examples, after reception of the radio audio signal, audio input unit 113 may be configured to prepare the radio audio signal for an audio signal processing by processing unit 115. For example, when the radio audio signal received from the remote audio source comprises an encoded signal, audio input unit 113 may comprise a decoder to decode the radio audio signal. E.g., radio receiver 125 may include the decoder.

[0040] In some implementations, as illustrated, audio input unit 113 may further comprise a sound detector 123 configured to detect sound in an ambient environment of the user and to provide an ambient audio signal representative of the detected sound. The input audio signal, which is received by processing unit 115, may then at least partially be based on the ambient audio signal. In some examples, sound detector 123 may be implemented as a microphone or a microphone array. In some examples, after detection of the sound in the ambient environment, audio input unit 113 may be configured to prepare the ambient audio signal for an audio signal processing by processing unit 115. For example, audio input unit 113 may comprise an analog-to-digital converter to convert the ambient audio signal, as detected by sound detector 123, from an analog signal into a digital signal. E.g., sound detector 123 may include the analog-to-digital converter.

[0041] Processing unit 115 is configured to receive the input audio signal from audio input unit 113. E.g., when audio input unit 113 comprises sound detector 123, the input audio signal may be based on the ambient audio signal and / or, when audio input unit 113 comprises radio receiver 125, the input audio signal may be based on the radio audio signal. Processing unit 115 is further configured to provide for audio signal processing of the input audio signal in different operational modes including a first operational mode for providing the output audio signal so as to compensate for a hearing loss of the user, and a second operational mode for providing the output audio signal as a stimulus for performing an REM. In the first operational mode, the audio signal processing comprises amplifying, in an amplification operation, the input audio signal according to a transfer function. In a second operational mode, processing unit is configured to perform the audio signal processing by processing the radio audio signal as the input audio signal, wherein the audio signal processing comprises the amplification operation. In some examples, in the second operational mode, the audio signal processing comprises, in addition to the amplification operation, modifying, in a stimulus preparation operation, a property of the input audio signal so as to provide for a modified audio signal adapted for conditions required for the REM. Those and other implementations are further described in the description that follows.

[0042] Different operational modes of processing unit 115, including the first operational mode and the second operational mode, may be implemented as different audio signal processing routines executed by processing unit 115. The audio signal processing routines may include an audio signal amplification module 116. Audio signal amplification module 116 can be configured to provide for the amplification operation by amplifying the audio signal according to the transfer function. In some implementations, as illustrated, the audio signal processing routines may further include and a stimulus preparation module 117. Stimulus preparation module 117 can be configured to provide for the stimulus preparation operation by modifying a property of the audio signal to adapt the audio signal for conditions required for the REM.

[0043] Processing unit 115 is not depicted in detail. Processing unit 115 may comprise a data storage, e.g., a memory, on which audio signal processing routines are stored. Processing unit 115 may further comprise a computing device for executing the audio signal processing algorithms stored on the data storage. The computing device may comprise a processor, in particular a central processing unit (CPU). The computing device may further comprise a main storage.

[0044] Audio output unit 119 may be implemented by any suitable audio output device configured to output sound based on the output audio signal to the user. To this end, audio output unit 119 may include an electroacoustic transducer. For example, audio output unit 119 may be implemented as a receiver of a hearing aid or a loudspeaker of an earbud.

[0045] FIG. 4 illustrates hearing device 111 when processing unit 115 is operating in a first operational mode 121 for providing the sound outputted by audio output unit 119 to compensate for a hearing loss of the user. First operational mode 121 corresponds to a normal operational mode which can be performed during a regular usage of hearing device 111 by the user. An input audio signal received by processing unit 115 may comprise an ambient audio signal A provided by sound detector 123. Alternatively or additionally, the input audio signal received by processing unit 115 may comprise a radio audio signal B provided by radio receiver 125. The input audio signal is inputted to audio signal amplification module 116 executed by processing unit 115.

[0046] As illustrated, when the input audio signal comprises one of the ambient audio signal A or the radio audio signal B, the input audio signal may be inputted into audio signal amplification module 116 via a respective signal path 126, 127. When the input audio signal comprises both the ambient audio signal A and the radio audio signal B, ambient audio signal A may be inputted into audio signal amplification module 116 via first signal path 126, and radio audio signal B may be inputted into audio signal amplification module 116 via second signal path 127. First and second signal paths 126, 127 may be separate or may partially overlap. E.g., ambient audio signal A and radio audio signal B may be mixed before inputting the mixed input audio signal into audio signal amplification module 116 via a single signal path. To this end, a mixing module, which may be implemented as an audio signal processing routine, may be executed by processing unit 115 before executing audio signal amplification module 116 based on the mixed signal.

[0047] Further, in addition to the amplification operation performed by audio signal amplification module 116, other audio signal processing routines may be performed by processing unit 115 on input audio signal A, B, e.g., before and / or after performing the amplification operation on the input audio signal, as may serve a particular implementation. The additional audio signal processing routines may include one or more of, e.g., noise cancelling, feedback cancelling, beamforming, speech enhancement, audio signal classification, performing an audio signal processing program associated with a current acoustic scene and / or depending on the audio signal classification, own voice detection, acoustic object separation, binaural synchronization, and / or the like.

[0048] Audio signal amplification module 116 is configured to amplify input audio signal A, B according to a transfer function. The transfer function may generally define a relationship between the input audio signal and the output audio signal, e.g., in the form of a frequency dependent representation of the amplification of the input audio signal and / or a representation of a frequency response of hearing device 111.

[0049] In some implementations, audio signal amplification module 116 is configured to allow for a customization of the transfer function, e.g., by adjusting one or more parameters of the transfer function, to match specific needs of an individual user, e.g., to compensate for an individual hearing loss of the user. In particular, by customizing the transfer function, hearing device 111 may be fitted to the specific needs and / or individual hearing loss. In some examples, the fitting of hearing device 111 may comprise an initial step in which the transfer function is customized based on a measurement of a hearing loss of the user, e.g., based on an audiogram. The fitting of hearing device 111 may further comprise a verification step in which it is verified whether the output audio signal matches the prescribed targets. Such a verification may be based on an REM. The fitting of hearing device 111 may further comprise a fine-tuning step in which the transfer function is further customized, e.g., fine-tuned, depending on the verification step, e.g., to provide for a better match of the output audio signal with the prescribed targets.

[0050] In some implementations, the transfer function may comprise a gain model. E.g., the transfer function may at least partially be represented by the gain model. The gain model may define an amplification of the input audio signal provided at different frequencies and / or at different signal levels. E.g., the gain model may include one or more parameters defining a frequency-specific gain. The gain model may further include one or more parameters defining how the gain changes with input level, e.g., compression ratios and / or mappings of different input levels to output levels. In some examples, the customizing of the transfer function, e.g., when fitting hearing device 111 to the specific needs and / or individual hearing loss of the user, may be performed by adjusting one or more parameters of the gain model.

[0051] By the processing of input audio signal A, B, which includes the amplification of input audio signal A, B by amplification module 116, and may optionally include applying other audio signal processing routines on input audio signal A, B as described above, an output audio signal O is obtained by processing unit 115. Output audio signal O is transmitted, via a signal path 128, to audio output unit 119 for outputting sound based on output audio signal O.

[0052] FIG. 5 illustrates hearing device 111 when processing unit 115 is operating in a second operational mode 131 for providing the outputted sound as a stimulus for performing an REM. In the illustrated example, the second operational mode 131 is performed in a first variant. The first variant has the purpose to provide for an audio signal processing of radio audio signal B to obtain an output audio signal suitable as a stimulus for performing the REM. To this end, radio audio signal B is received by processing unit 115 as the input audio signal from audio input unit 113. In some examples, only radio audio signal B is received from radio receiver 125 via signal path 127. In other examples, ambient audio signal A may additionally be received from sound detector 123 via signal path 126. Ambient audio signal A may then be disregarded, e.g., attenuated or suppressed, for the audio signal processing performed to provide the stimulus.

[0053] Radio audio signal B can be received by radio receiver 125 from a remote audio source 135 via RF radiation 136. In some examples, remote audio source 135 is implemented as a computing device, e.g., a personal computer, and / or a portable device, e.g., a smartphone, smartwatch, tablet, and / or the like. Remote audio source 135 may be controlled to transmit radio audio signal B to radio receiver 125 at specific times, e.g., upon request of the user and / or a query send by hearing device 111 via RF radiation and / or initiated by a computer program executed on a computing device controlling remote audio source 135. E.g., the computer program may be executed during performing the REM and / or may be intended for usage in conjunction with the REM.

[0054] In some implementations, remote audio source 135 is configured to provide radio audio signal B fulfilling one or more properties required for radio audio signal B to be used as a stimulus in REM. In some implementations, after radio audio signal B is received by radio receiver 125, one or more properties of radio audio signal B may be modified by stimulus preparation module 117 in order to be used as a stimulus in REM, as further described below.

[0055] The required properties of radio audio signal B for usage as a stimulus in REM may comprise a calibration of the signal, e.g., to ensure that the sound level presented to the ear is precise, and / or a consistency of the signal, such that the stimulus can be reliably reproduced, and / or a minimum duration of the signal allowing to provide a stimulus sufficient to obtain reliable measurements, e.g., a duration of several seconds. The required properties may further include a predetermined frequency range, which may be selected to ensure a desired and / or comprehensive frequency evaluation. The properties may also include a predetermined intensity level, which may be selected to simulate a specific listening environment and / or may be selectable from different intensity levels to provide for different listening environments. The properties may also include a type of the stimulus including, e.g., one or more of a stimulus including speech, a pure tone, a swept tone, a warble tone, a complex tone, a composite signal containing multiple frequencies, a stimulus including music, or a noisy stimulus such as white noise, pink noise and speech noise.

[0056] After radio audio signal B is received by processing unit 115, radio audio signal B is inputted into audio signal amplification module 116 via signal path 127. Audio signal amplification module 116 is configured to amplify the input audio signal according to the transfer function. Audio signal amplification module 116 may then operate correspondingly as when employed in the first operational mode 121, as described above in conjunction with Fig. 4. After the audio signal processing, the output audio signal O obtained by processing unit 115 is transmitted, via signal path 128, to audio output unit 119. Audio output unit 119 can then output sound 139 based on output audio signal O as a stimulus for the REM.

[0057] Employing radio audio signal B provided by radio receiver 125 as an input audio signal to produce a stimulus for REM, as described above, can offer multiple advantages. At first, transmitting radio audio signal B from remote audio source 135 to radio receiver 125 via RF radiation is silent. Accordingly, no sound needs to be produced and transmitted in the room between remote audio source 135 and hearing device 111 in order to be detected at the position at which hearing device 111 is worn by the user. Therefore, any sound, in particular noise, present in the room for performing REM does not interfere with the input audio signal. The input audio signal received by radio receiver 125 can thus be delivered from remote audio source 135 in an undisturbed manner so that it closely corresponds to an original pure form. This can be particularly useful when a stimulus for REM is intended to be presented with a rather small SPL at which a noisy environment would most eminently interfere with a sound transmitted as the input audio signal between remote audio source 135 and hearing device 111. For example, employing radio audio signal B as the input audio signal can be advantageous for providing a clean stimulus at a level of soft speech. In this way, requirements for the room in which the REM is preformed can be lowered in that the measurement environment can be more noisy and / or less quiet.

[0058] As another example, employing radio audio signal B as the input audio signal can be useful to avoid sound emission from remote audio source 135 which would lead to a noise pollution of the measurement environment. To illustrate, when a stimulus for REM is intended to be presented at a rather large SPL which would exceed a current noise level in the environment, transmitting the input audio signal as a sound emitted by remote audio source 135 could disturb people present in the same room or next door. In contrast, transmitting the input audio signal as radio audio signal B has no impact on the current room acoustics. For example, employing radio audio signal B can also be advantageous when providing a stimulus at a level of loud speech. The measurement environment may then only slightly be impacted by stimulus S outputted by audio output unit 119 of hearing device 111 which may be negligible when compared to a corresponding sound which would be emitted directly into the room by remote audio source 135.

[0059] Secondly, transmitting radio audio signal B from remote audio source 135 to radio receiver 125 via RF radiation as an input audio signal for producing a stimulus for REM has another advantage that a generation of the input audio signal can be facilitated by making use, at least to a certain extent, of features and / or equipment and / or devices and / or hardware and / or software already present in a conventional hearing device. For example, as described above, radio receiver 125 may also be employed in first operational mode 121, corresponding to a normal operational mode of hearing device 111, for receiving radio audio signal B, e.g., from an auxiliary user device such as a smart phone, tablet, remote microphone, personal computer and / or the like. Thus, applying the user device and / or another device dedicated for performing REM to transmit radio audio signal B for the purpose of providing a stimulus for the REM can be implemented with rather low constructional effort. In this way, manufacturing costs can be reduced and a provision of hearing device 111 with additional space consuming components can be minimized.

[0060] FIG. 6 illustrates hearing device 111 when processing unit 115 is operating in another implementation 132 of the first variant of the second operational mode for providing an audio signal processing of radio audio signal B to produce a stimulus for performing an REM by the outputted sound. After radio audio signal B is received by processing unit 115, radio audio signal B is inputted into stimulus preparation module 117 via signal path 127. Stimulus preparation module 117 is configured to modify, in a stimulus preparation operation, a property of the radio audio signal B so as to provide for a modified input audio signal M adapted for conditions required for the REM. After performing the stimulus preparation operation, modified input audio signal M is inputted into audio signal amplification module 116 via a signal path 133. Audio signal amplification module 116 is then configured to amplify input audio signal M according to the transfer function. Audio signal amplification module 116 may then operate correspondingly as when employed in the first operational mode 121. After the audio signal processing, the output audio signal O obtained by processing unit 115 is transmitted, via signal path 128, to audio output unit 119. Audio output unit 119 can then output sound 139 based on output audio signal O as a stimulus for the REM.

[0061] In some implementations, as illustrated, the stimulus preparation operation is performed by stimulus preparation module 117 before the amplification operation is performed by audio signal amplification module 116. In some other implementations, the stimulus preparation operation is performed after the amplification operation. In some implementations, in addition to the stimulus preparation operation and the amplification operation, other audio signal processing routines may be performed by processing unit 115 on radio audio signal B, e.g., before and / or after and / or between performing the stimulus preparation by stimulus preparation module 117 and performing the amplification operation by audio signal amplification module 116. Examples of additional audio signal processing routines are described above in conjunction with Fig. 4.

[0062] In some implementations, when switching between the first operational mode and the second operational mode, processing unit 115 is configured to activate, in addition to audio signal amplification module 116, stimulus preparation module 117 in the second operational mode, and to deactivate stimulus preparation module 117 in the first operational mode. In some implementations, stimulus preparation module 117 and audio signal amplification module 116 can be combined to a single module which can be executed by processing unit 115 in the second operational mode, and audio signal amplification module 116 can be provided as another module which can be executed by processing unit 115 in the first operational mode. Signal paths 126, 127, 128, 133 are indicated in the figures for illustrative purposes only and may be implemented, as appreciated by a skilled person, in various ways, e.g., as a sequence of instructions and / or routines of an audio processing program, a sequence of multiple audio processing programs, signal lines, and / or the like.

[0063] Stimulus preparation module 117 is configured to adapt the input audio signal for conditions required for REM by modifying at least one property of the input audio signal, which may include an SPL represented by the input audio signal and / or a frequency range included in the input audio signal and / or a shape of a frequency spectrum included in the input audio signal and / or a vocal effort represented by the input audio signal.

[0064] To illustrate, the SPL of stimulus S presented to the user may be selected to represent a certain listening environment and / or a speech level the user may encounter during daily life. The SPL represented by the input audio signal may thus be modified in order to be representative for such a listening environment and / or speech level. In some examples, the SPL of the input audio signal may be selected from different speech levels. The different speech levels may comprise a level of soft speech, which may correspond to an SPL range between 45 and 55 dB SPL, and / or a level of average speech, which may correspond to an SPL range between 60 and 70 dB SPL, and / or a level of loud speech, which may correspond to an SPL range between 75 and 85 dB SPL. Accordingly, stimulus preparation module 117 may be configured to modify the SPL represented by the input audio signal such that the SPL corresponds to the selected speech level. The speech level may also be indicative of a vocal effort represented by stimulus S, e.g., when the stimulus includes speech. The vocal effort may be characterized as a spectrum of the voice depending on a loudness of the voice.

[0065] As another example, the frequency range included in the input audio signal may be modified to include a standard frequency range, which may correspond to frequencies between 250 Hz and 8.000 Hz, sufficient to cover a majority of speech sounds. The frequency range included in the input audio signal may also be modified to include an extended high-frequency range, which may include frequencies up to 10.000 Hz or higher, e.g., to improve the clarity of high-frequency speech sounds (e.g., fricatives) and / or enhance the perception of music and environmental sounds. The frequency range included in the input audio signal may also be modified to include a low-frequency range, which may include frequencies down to 125 Hz or below, ensuring that the low frequency range is also evaluated, e.g., for users with low-frequency hearing loss and / or ensuring that low-frequency sounds are not overly amplified, which could lead to discomfort and / or feedback. As another example, the shape of a frequency spectrum included in the input audio signal may be modified to account for a more homogenous frequency distribution and / or a frequency distribution targeted for evaluating an individual hearing loss and / or to mimic a certain amount of a vocal effort and / or to resemble other natural sounds and / or the like.

[0066] Employing stimulus preparation module 117 in the first variant 132 of the second operational mode to adapt radio audio signal B for conditions required for REM can be employed to lower the requirements of radio audio signal B transmitted from remote audio source 135 to radio receiver 125 and / or to offer a better flexibility for modifying the radio audio signal B to produce the stimulus. To illustrate, radio audio signal B as transmitted from remote audio source 135 may be employed for performing REMs in various hearing devices worn, e.g., by different users. Modifying radio audio signal B by stimulus preparation module 117, as implemented in the various hearing devices, can then be employed to account for device specific and / or user specific differences directly on site by the processing performed in each hearing device, wherein radio audio signal B transmitted to each hearing device can be equal. Further, stimulus preparation module 117 may be employed to perform multiple REMs with different stimuli by the same hearing device, wherein the different stimuli can be based on an equal radio audio signal B by a different modification of radio audio signal B.

[0067] Overall, the first variant 131, 132 of the second operational mode, as described above in conjunction with Figs. 5 and 6, allows producing an REM stimulus by means of radio audio signal B transmitted from remote audio source 135 to radio receiver 125 via RF radiation in a silent way without impacting the room acoustics and without being impacted by the room acoustics. First variant 131, 132 of the second operational mode may thus also be denoted as a silent stimulus mode. Stimulus 139 outputted by hearing device 111 may also be denoted as a silent stimulus.

[0068] FIG. 7 illustrates hearing device 111 when processing unit 115 is operating in a second variant 141 of the second operational mode for providing the outputted sound as a stimulus 149 for performing an REM. Second variant 141 has the purpose to provide for an audio signal processing of ambient audio signal A to obtain an output audio signal suitable as a stimulus for performing the REM. To this end, ambient audio signal A is received by processing unit 115 as the input audio signal from audio input unit 113. In some examples, only ambient audio signal A is received from sound detector 123 via signal path 126. In other examples, radio audio signal B may additionally be received from radio receiver 125 via signal path 127. Radio audio signal B may then be disregarded, e.g., attenuated or suppressed, for the audio signal processing performed to provide the stimulus.

[0069] Ambient audio signal A can be based on a sound 146 detected by sound detector 123 in the ambient environment of the user wearing hearing device 111. As illustrated, sound 146 may be produced in the ambient environment by an external sound source 145, which may be located in the environment, e.g., an external loudspeaker, which may be located at a distance to the user. Ambient audio signal A provided by sound detector 123 may be representative of sound 146. In some implementations, external sound source 145 is configured to provide sound 146 fulfilling one or more properties required for ambient audio signal A to be used as a stimulus in REM. In some implementations, after ambient audio signal A is provided by sound detector 123, one or more properties of ambient audio signal A may be modified by stimulus preparation module 117 in order to be used as a stimulus in REM, as further described below. The required properties of ambient audio signal A for usage as a stimulus in REM may comprise one or more of a calibration, a consistency, and a minimum duration of the signal, as well as a predetermined frequency range and / or a predetermined intensity level and / or a certain type of the stimulus represented by the signal.

[0070] After ambient audio signal A is received by processing unit 115 as the input audio signal, ambient audio signal A is inputted into stimulus preparation module 117 via signal path 127 to obtain modified input audio signal M in the stimulus preparation operation, which is then inputted into audio signal amplification module 116 via a signal path 133 to amplify the input audio signal according to the transfer function, corresponding to the processing of radio audio signal B performed in first variant 132 of the second operational mode described above. In some examples, ambient audio signal A may be modified differently in the stimulus preparation operation performed by stimulus preparation module 117 in second variant 141 of the second operational mode as compared to radio audio signal B when the stimulus preparation operation is performed in first variant 132 of the second operational mode. E.g., an SPL and / or a frequency range and / or a vocal effort represented by the input audio signal may be modified to a different adjustment. In some examples, ambient audio signal A may be modified to account for a calibration with regard to one or more properties of sound 146 emitted by external sound source 145, as further described below in conjunction with Fig. 8. In some other examples, ambient audio signal A may be modified to an equal adjustment as radio audio signal B in first variant 131, 132 of the second operational mode.

[0071] Employing ambient audio signal A provided by sound detector 123 as an input audio signal to produce a stimulus for REM, as described above, can be beneficial, when compared to employing radio audio signal B provided by radio receiver 125 for this purpose, in that it can provide for an actual sound field 146 within the measurement environment. In this way, a natural listening environment, in which the user will apply hearing device 111 on a daily basis, may be simulated more accurately, e.g., to provide for a more natural listening experience also during the REM.

[0072] Further, when presenting the stimulus to the user without providing sound field 146, one or more components and / or features and / or properties of hearing device 111, which may be used during a normal operation of hearing device 111 in first operational mode 121, as illustrated in Fig. 4, may be unused and / or bypassed during the REM. Such components may comprise sound detector 123 and / or a vent which may be provided in hearing device 111 for delivering sound 146 from the environment directly into the ear canal as direct sound and / or an acoustic sealing of hearing device 111 inside the ear canal to prevent the environmental sound to directly enter the ear canal, at least to a certain extent. Such features may comprise audio processing routines intended for processing ambient audio signal A. Such properties may comprise a shape and / or position of hearing device 111 when inserted inside the ear canal, which may cause leakage of sound, at least when hearing device 111 is configured in an inappropriate way. Checking and / or testing such components and / or features and / or properties within the framework of an REM may thus require a provision of sound field 146.

[0073] On the other hand, relying on a detection of sound field 146 by sound detector 123 for producing an REM stimulus may give rise to disadvantages and / or difficulties, which have already been noted above, e.g., in the context of some benefits of radio audio signal B for producing the stimulus. In particular, a stimulus with a small SPL provided via sound field 146 may be negatively impacted in a noisy environment and / or a stimulus with a large SPL provided via sound field 146 may impact the room acoustics in a negative way. To mitigate those disadvantages, the stimulus may be produced based on ambient audio signal A in a case in which sound field 146 produced by external sound source 145 is less prone to be impacted by a noisy environment and / or less likely to impact the environment by the produced sound. For example, employing ambient audio signal A as the input audio signal can be advantageous for providing a stimulus at a level of average speech and / or, more generally, when sound field 146 represented by ambient audio signal A is sufficiently uncompromised by environmental noise and / or low enough for comfortable room acoustics.

[0074] Thus, in the second variant 141 of the second operational mode, as described above in conjunction with Fig. 7, REM stimulus 149 can be produced by means of ambient audio signal A based on detected ambient sound 146. Second variant 141 of the second operational mode may thus also be denoted as an ambient stimulus mode. Stimulus 149 outputted by hearing device 111 may also be denoted as an ambient stimulus.

[0075] FIG. 8 illustrates hearing device 111 when processing unit 115 is performing a calibration operation 151 for calibrating the stimulus provided in the second operational mode. Calibration operation 151 may be performed by employing a modification parameter adjustment module 155. E.g., modification parameter adjustment module 155 may be implemented as an audio signal processing routine executed by processing unit 115.

[0076] As illustrated, after ambient audio signal A is received by processing unit 115, ambient audio signal A is inputted into modification parameter adjustment module 155. Modification parameter adjustment module 155 is configured to adjust, depending on ambient audio signal A, one or more processing parameters applied in the stimulus preparation operation when processing ambient audio signal A. To this end, modification parameter adjustment module 155 may adjust stimulus preparation module 117 via a signal path 158. The adjustment may be performed, e.g., so as to calibrate the stimulus preparation operation, as performed by stimulus preparation module 117, to external sound source 145 emitting sound 146 in the ambient environment. Stimulus preparation module 117 may then be configured to modify the property of the input audio signal based on the adjusted processing parameters.

[0077] For determining the adjustment of the one or more processing parameters, modification parameter adjustment module 155 can be configured to compare ambient audio signal A to a reference quantity. The reference quantity can be indicative of one or more properties of the ambient audio signal A which are required for providing the stimulus. The adjustment of the one or more processing parameters can then be performed based on the comparison. In some examples, the stimulus preparation operation, as performed by stimulus preparation module 117, may thus be calibrated with regard to one or more properties of sound 146 emitted by external sound source 145.

[0078] Calibration operation 151 may be performed before continuing, in the second operational mode, with the audio signal processing of ambient audio signal A to obtain output audio signal O as a stimulus for performing the REM, according to second variant 141 of second operational mode illustrated in Fig. 6. In a first step, the reference quantity may be provided to modification parameter adjustment module 155. In some instances, the reference quantity may be transferred to hearing device 111 from an external device, e.g., an external computing device, in order to be received by processing unit 115. In some instances, the reference quantity may be stored in a memory of processing unit 115.

[0079] In a second step, a calibration sound 156 may be emitted by external sound source 145 and detected by sound detector 123. After ambient audio signal A representative of the detected calibration sound 156 is received by processing unit 115, modification parameter adjustment module 155 can compare ambient audio signal A to the reference quantity. In a third step, modification parameter adjustment module 155 can adjust the one or more processing parameters applied in the stimulus preparation operation depending on the comparison.

[0080] Subsequently, sound 146 to be used as a stimulus in REM may be emitted by external sound source 145 and detected by sound detector 123. After ambient audio signal A representative of the detected sound 146 is received by processing unit 115, stimulus preparation module 117 can modify one or more properties of ambient audio signal based on the adjusted processing parameters in order to be used as a stimulus in REM, according to second variant 141 of second operational mode. After the audio signal processing, which further comprises amplifying input audio signal M according to the transfer function, output audio signal O is obtained by processing unit 115 based on which sound can be outputted by audio output unit 119 as a stimulus for the REM.

[0081] Accordingly, the reference quantity and / or calibration sound 156, as provided to modification parameter adjustment module 155 for performing calibration operation 151, may be selected to be suitable for determining the adjustment of the processing parameters based on comparing ambient audio signal A representative of the detected calibration sound 156 with the reference quantity. In some examples, the calibration sound may be provided as a continuous sound and / or a sequence of sounds covering a range of frequencies necessary for an accurate calibration. In some examples, the reference quantity may be provided depending on one or more characteristics of external sound source 145, e.g., a frequency response, shape, range, SPL, and / or the like. In some examples, the reference quantity may be provided as an audio signal representative of a sound fulfilling one or more properties required for the stimulus. In some examples, the reference quantity provided as the audio signal may be representative of one or more properties of calibration sound 156, e.g., a duration and / or frequency range and / or frequency content of calibration sound 156.

[0082] In some examples, by performing calibration operation 151, the specifications and / or requirements for external sound source 145 such that it is suitable for providing sound 146, based on which a stimulus for REM can be provided, can be lowered. E.g., in place of a loudspeaker specialized for REM to ensure a precise sound delivery and consistent performance, a multi-purpose speaker system may be used, which may exhibit a lower performance, e.g., with regard to a flatness of the frequency response, a low distortion, a sound delivery focused toward the user wearing hearing device 111, and / or a rather high output level. Calibration operation 151 can thus allow to employ sound emitted by a lower quality external sound source 145 as a stimulus for performing the REM when performing second variant 141 of the second operational mode.

[0083] FIG. 9 illustrates an implementation 152 of the calibration operation illustrated in Fig. 8. A signal C containing the reference quantity is received by processing unit 115 from radio receiver 125 via signal path 127 so that modification parameter adjustment module 155 can compare ambient audio signal A to reference quantity C. Radio receiver 125 is configured to obtain signal C comprising the reference quantity from an external device 165, e.g., an external computing device, via RF radiation 166. In some examples, external device 165 may be implemented as remote audio source 135. Signal C containing the reference quantity may then be implemented as a radio audio signal. In some examples, radio audio signal C can be representative of a sound fulfilling one or more properties required for a stimulus for REM.

[0084] In some examples, before operating in the second operational mode, processing unit 115 can be configured to perform calibration operation 151, 152 in preparation of performing second variant 141 of the second operational mode in order to produce an REM stimulus by means of ambient audio signal A. Combining operation 151, 152 with second variant 141 of the second operational mode may be denoted as an ambient stimulus mode 141 including external sound source calibration 151, 152.

[0085] In some examples, when operating in the second operational mode, processing unit 115 can be configured to perform first variant 131, 132 of the second operational mode and second variant 141 of the second operational mode in a sequence so that a plurality of stimuli may be outputted by audio output unit 119 in the sequence. Combining first variant 131, 132 and second variant 141 of the second operational mode in a sequence may be denoted as a third operational mode 131, 132, 141, or a silent and ambient stimulus mode 131, 132, 141.

[0086] Accordingly, when operating in silent and ambient stimulus mode 131, 132, 141, the above described advantages of both modes 131, 132, 141 may be combined. In some examples, producing a stimulus in silent stimulus mode 131, 132 may be employed when advantages of radio audio signal B prevail advantages of ambient audio signal A, e.g., when a stimulus based on sound 146 emitted by external sound source 145 would be negatively impacted in a noisy environment and / or sound 146 would impact the room acoustics in a negative way. This may be the case, e.g., for a stimulus with a small SPL and / or a stimulus with a large SPL. In some examples, ambient stimulus mode 141, which may include or exclude external sound source calibration 151, 152, may be employed for producing a stimulus at least one time within the sequence of stimuli. The at least one stimulus produced in ambient stimulus mode 141 may be selected as a stimulus which production is less impacted in a noisy environment and / or would have less negative impact on the room acoustics as compared to the production of at least another stimulus in ambient stimulus mode 141, which would then be produced in silent stimulus mode 131, 132.

[0087] In some examples, a sequence of at least two stimuli may be produced in silent and ambient stimulus mode 131, 132, 141, wherein a stimulus with a smaller SPL, such as a soft speech level, is produced in silent stimulus mode 131, 132, and a stimulus with a larger SPL, such as an average speech level, is produced in ambient stimulus mode 141. In some examples, a sequence of at least two stimuli may be produced in silent and ambient stimulus mode 131, 132, 141, wherein a stimulus with a larger SPL, such as a loud speech level, is produced in silent stimulus mode 131, 132, and a stimulus with a smaller SPL, such as an average speech level, is produced in ambient stimulus mode 141. In some examples, a sequence of at least three stimuli may be produced in silent and ambient stimulus mode 131, 132, 141, wherein a stimulus with a smaller SPL, such as soft speech level, and a stimulus with a larger SPL, such as a loud speech level, is produced in silent stimulus mode 131, 132, and a stimulus with an intermediate SPL, such as an average speech level, is produced in ambient stimulus mode 141.

[0088] FIG. 10 illustrates another exemplary hearing device 211 configured to be worn at an ear of a user. Hearing device 211 comprises an ear-canal microphone 219 communicatively coupled to processing unit 115. Ear-canal microphone 219 is configured to provide an in-the-ear audio signal I indicative of a sound 218 detected inside the ear canal. Processing unit 115 is configured to provide for a processing of the in-the-ear audio signal I to obtain an output data signal R. In-the-ear audio signal I can be received by processing unit 115 via a signal path 214. Hearing device 211 further comprises a data output unit 213 communicatively coupled to processing unit 115. Processing unit 115 can transmit output data signal R to data output unit 213 via a signal path 220. Data output unit 213 is configured to output the output data signal R.

[0089] In some implementations, data output unit 213 can include a data transceiver 215 configured to output the output data signal R via RF radiation 217. For instance, output data signal R may be transmitted in accordance with a Bluetooth ™< protocol and / or by any other type of RF communication. Output data signal R may be transmitted to a computing device 212, e.g., a personal computer, smartphone, smartwatch, tablet, and / or the like, which may be stationary or worn by the user. In some examples, remote audio source 135 is integrated with computing device 212. Computing device 212 may then be configured to transmit radio audio signal B to radio receiver 125 via RF radiation 136.

[0090] Processing unit 115 is configured, in a REM evaluation operation 221, to evaluate in-the-ear audio signal I. To this end, an REM evaluation module 216 may be implemented as an audio signal processing routine executed by processing unit 115. In some examples, REM evaluation module 155 can evaluate in-the-ear audio signal I by determining an SPL of sound in the ear canal represented by in-the-ear audio signal I, e.g., in dependence of a frequency of the sound. E.g., the SPL may be determined for a plurality of frequencies of the sound represented by in-the-ear audio signal I. In some examples, a real-ear aided gain (REAG) may be determined based on in-the-ear audio signal I, e.g., based on the SPL of the sound in the ear canal. In some examples, in-the-ear audio signal I may be evaluated by preparing a further evaluation of the REM, e.g., to determine the REAG, which may comprise a frequency decomposition of in-the-ear audio signal I, an amplification, a noise reduction and / or the like. Output data signal R can then be representative of the evaluated in-the-ear audio signal I. After receiving output data signal R, computing device 212 may be employed to further evaluate output data signal R with regard to the REM and / or with regard to a fitting of hearing device 211 to an individual hearing loss of the user and / or to present a result of the REM to the user and / or another person interested in the result, e.g., an HCP.

[0091] In some examples, when operating in the second operational mode, processing unit 115 can be configured to perform REM evaluation operation 221 subsequent to performing first variant 131, 132 and / or second variant 141 of the second operational mode, as illustrated in Figs. 5 - 7. In particular, second variant 141 may be performed including or excluding external sound source calibration 151, 152, as illustrated in Figs. 8 and 9. Combining operation 221 with first variant 131, 132 and / or second variant 141 of the second operational mode may be denoted as an REM mode for stimulus provision and response evaluation.

[0092] In some examples, when operating in the second operational mode, processing unit 115 can be configured to perform the REM mode for stimulus provision and response evaluation repeatedly, wherein at different repetitions different stimuli are provided in the first variant 131, 132 and / or second variant 141 of the second operational mode, which may be denoted as an REM mode for repeated stimulus provision and response evaluation. In some examples, at least one of the repetitions may comprise producing stimulus 139 in silent stimulus mode 131, 132, e.g., for a stimulus with a smaller SPL and / or a stimulus with a larger SPL, and at least one of the repetitions may comprise producing stimulus 149 in ambient stimulus mode 141, e.g., for a stimulus with an intermediate SPL.

[0093] FIG. 11 illustrates another exemplary hearing device 231 configured to be worn at an ear of a user. Hearing device 231 comprises a probe tube 235 attachable to ear-canal microphone 219, e.g., to a sound inlet of ear-canal microphone 219. Probe tube 235 may be attached to ear-canal microphone 219 when operating in the second operational mode.

[0094] Probe tube 235 has a length smaller than a distance between ear-canal microphone 219 and the tympanic membrane when hearing device 231 is inserted into the ear canal. E.g., the length of probe tube 235 may be selected such that a sound inlet of probe tube 235 has a distance of less than 10 mm, e.g., within about 5 mm, from the tympanic membrane when attached to ear-canal microphone 219. Thus, a capture of the sound with a characteristic SPL close to the eardrum ear-can be ensured. To illustrate, when producing a stimulus for REM inside the ear canal, the SPL of the stimulus may vary considerably, e.g., due to standing waves, ear canal resonances, reflections and diffractions, individual variabilities of the shape and size of the ear canal, and / or the like.

[0095] In some examples, probe tube 235 may be attached to ear-canal microphone 219 to calibrate REM evaluation operation 221 when performed without probe tube 235, as illustrated in Fig. 10. To this end, in a probe tube REM evaluation operation 241, REM evaluation operation 221 may be performed with the attached probe tube 235. In-the-ear audio signal I and / or output data signal R obtained in probe tube REM evaluation operation 241 can then be used as reference data to calibrate REM evaluation operation 221 when performed without attaching probe tube 235 to ear-canal microphone 219. In some examples, for the purpose of calibrating REM evaluation operation 221, it may also be that REM evaluation operation 221 without attached probe tube 235 is performed in addition to probe tube REM evaluation operation 241 under the same conditions, e.g., with the same stimulus. The reference data used to calibrate REM evaluation operation 221 may then be obtained by comparing and / or relating audio signal I and / or output data signal R as obtained in probe tube REM evaluation operation 241 and as obtained in REM evaluation operation 221 without attached probe tube 235. In some examples, the reference data may be stored in a memory of processing unit 115 and / or a memory of computing device 135, 212. The reference data can then be used in REM evaluation operation 221, e.g., by REM evaluation module 216, to calibrate, e.g., normalize, in-the-ear audio signal I and / or output data signal R with regard to a measurement result obtained with attached probe tube 235.

[0096] FIG. 12 illustrates another exemplary hearing device 251 configured to be worn at an ear of a user. Hearing device 251 represents some implementations of hearing device 221, 231 described above, wherein radio receiver 125 is integrated with data transceiver 215 as a single unit. Data transceiver 215 can thus be configured to receive radio audio signal B from remote audio source 135 and to transmit output data signal R, e.g., to computing device 212. For example, data transceiver 215 may be configured to receive radio audio signal B and to transmit output data signal R in accordance with a Bluetooth ™< protocol and / or by any other type of RF communication. In some examples, computing device 212 may be configured to transmit radio audio signal B and to receive output data signal R.

[0097] FIG. 13 illustrates an exemplary implementation of hearing device 111, 211, 231, 251 as a RIC hearing aid 261. RIC hearing aid 261 comprises a BTE part 270 configured to be worn at an ear at a wearing position behind the ear, and an ITE part 280 configured to be worn at the ear at a wearing position at least partially inside an ear canal of the ear. BTE part 270 comprises a BTE housing 271 configured to be worn behind the ear. BTE housing 271 accommodates processing unit 115 communicatively coupled to sound detector 123 and radio receiver 125, which may also be employed as data transceiver 215. BTE part 220 further includes a battery 277 as a power source. ITE part 280 is an earpiece comprising an ITE housing 281 at least partially insertable into the ear canal. ITE housing 281 accommodates audio output unit 119 and ear-canal microphone 219. BTE part 270 and ITE part 280 are interconnected by a cable 274. Processing unit 115 is communicatively coupled to audio output unit 119 and to ear-canal microphone 219 of ITE part 280 via cable 274 and cable connectors 272, 273 provided at BTE housing 271 and ITE housing 281.

[0098] FIG. 14 illustrates a hearing system 301 for performing REM including hearing device 111 and remote audio source 135 and / or external sound source 145. System 301 further comprises probe 12 as described above in conjunction with Figs. 1, 2. Probe 12 is communicatively coupled with a computing device 302 which may be implemented with remote audio source 135.

[0099] One or more stimuli for the REM can be produced by hearing device 111 by processing input audio signal 136, 146 in second operational mode 131, 132, 141. In some examples, at least one stimulus is produced by processing radio audio signal 136 in silent stimulus mode 131, 132. In some examples, at least one stimulus is produced by processing ambient audio signal 146 in ambient stimulus mode 131, 132. Ear canal probe 13 including a probe tube inserted into ear canal 26 of ear 25 at which hearing device 111 is worn can then be used to measure an SPL of the sound produced inside ear canal 26, e.g. a frequency response. The result of the REM can be evaluated by computing device 302.

[0100] FIG. 15 illustrates another hearing system 311 for performing REM including hearing device 211, or hearing device 231, 251, and remote audio source 135 and / or external sound source 145. After producing, by processing input audio signal 136, 146 in second operational mode 131, 132, 141, a stimulus for the REM by hearing device 211, output data signal R can be obtained by processing in-the-ear audio signal I detected by ear-canal microphone 219. Output data signal R can then be transmitted to computing device 212 via RF radiation 217.

[0101] FIG. 16 illustrates a block flow diagram for an exemplary method of operating a hearing device configured to be worn at an ear of a user. The method may be executed by processing unit 115 of hearing device 111, 211, 231, 251. In some implementations, at operation S11, after receiving the input audio signal which may comprise ambient audio signal A and / or radio audio signal B, first operational mode 121 is executed for obtaining output audio signal O so as to compensate for a hearing loss of the user by the sound outputted based on output audio signal O.

[0102] At operation S12, a switching from operating in first operational mode 121 to operating in second operational mode 131, 132, 141, 151, 152, 221, 241 is initiated. As illustrated, the switching between the first and second operational mode may be initiated depending on a control signal S, which may be received by processing unit 115. In some examples, control signal S may be generated depending on an input of the user and / or another person interested in performing an REM in the second operational mode. In some examples, control signal S may be generated based on an input on a user interface of hearing device 111, 211, 231, 251 and / or an input on computing device 212, which may then be transmitted to processing unit 115, e.g., in accordance with a Bluetooth ™< protocol and / or by any other type of RF communication.

[0103] At operation S13, after receiving input audio signal A and / or B, the second operational mode is executed for obtaining output audio signal O so as to provide a stimulus for REM by the sound outputted based on output audio signal O. The second operational mode may be implemented as one or more of operations 131, 132, 141, 151, 152, 221, 241 described above. To illustrate, in some instances, first variant 131, 132 of the second operational mode may be executed by processing radio audio signal B as the input audio signal, which may be received from remote audio source 135 by radio receiver 125. In some instances, second variant 141 of the second operational mode may be executed by processing ambient audio signal A as the input audio signal, which may be representative of sound emitted by external sound source 145 in the ambient environment of the user.

[0104] In some implementations, after providing the outputted sound as a stimulus for REM in operation S 13, a further operation may be performed in which REM evaluation operation 221, 241 is executed, wherein in-the-ear audio signal I is provided by ear-canal microphone 219 so as to obtain output data signal R.

[0105] In some implementations of the method illustrated in Fig. 16, after receiving input audio signal A and / or B, the second operational mode is executed at operation S 11. At operation S12, a switching from operating in the second operational mode to operating in the first operational mode is initiated, e.g., depending on control signal S. At operation S13, after receiving input audio signal A and / or B, the first operational mode is executed.

[0106] FIG. 17 illustrates a block flow diagram for another exemplary method of operating a hearing device configured to be worn at an ear of a user. The method may be implemented as an audio signal processing in the second operational mode, e.g., first variant 131, 132 and / or second variant 141 of the second operational mode. The method may be implemented in place of operation S11 and / or in place of operation S13 of the method illustrated in Fig. 16 when operating in the second operational mode. At operation S24, after receiving input audio signal A and / or B, a property of the input audio signal is modified in a stimulus preparation operation, e.g., by stimulus preparation module 117, so as to provide for modified audio signal M adapted for conditions required for REM. At operation S25, the modified audio signal M is amplified according to a transfer function in an amplification operation, e.g., by audio signal amplification module 116.

[0107] FIG. 18 illustrates a block flow diagram for another exemplary method of operating a hearing device configured to be worn at an ear of a user. The method may be implemented in calibration operation 151, 152 illustrated in Figs. 8 and 9. The method may be executed before performing audio signal processing in second variant 141 of the second operational mode, e.g., before operation S13 of the method illustrated in Fig. 16. At operation S31, after receiving input audio signal A and reference quantity C, ambient audio signal A and reference quantity C are compared. At operation S32, one or more processing parameters applied in the stimulus preparation operation executed by stimulus preparation module 117 in second variant 141 of the second operational mode in second variant 141 are adjusted based on the comparison. In some examples, when reference quantity C is obtained by radio receiver 125 from external device 165, external device 165 may be implemented as computing device 212 configured to receive output data signal R in REM evaluation operation 221, 241 and / or may include remote audio source 135 to provide reference quantity C as a radio audio signal.

[0108] FIG. 19 illustrates a block flow diagram for another exemplary method of operating a hearing device configured to be worn at an ear of a user. The method may be implemented in place of operation S11 and / or in place of operation S13 of the method illustrated in Fig. 16 when operating in the second operational mode. At operation S41, after receiving radio audio signal B, first variant 131, 132 of the second operational mode is executed for obtaining output audio signal O so as to provide a first stimulus for REM. In some examples, REM evaluation operation 221, 241 may then be executed. At operation S42, after receiving ambient audio signal A, second variant 141 of the second operational mode is executed for obtaining output audio signal O so as to provide a second stimulus for REM. In some examples, REM evaluation operation 221, 241 may then be executed again.

[0109] In some examples, the stimuli are provided such that the first stimulus has a smaller SPL than the second stimulus. Thereby, the circumstance may be favorably exploited that the first stimulus, which is produced based on processing of radio audio signal B, is hardly impacted by environmental noise, even at small values of the SPL of the first stimulus, wherein the second stimulus, as produced based on a processing of ambient audio signal A detected in the environment, can be increasingly affected by the environmental noise with an increasingly smaller SPL of the second stimulus and / or an increasingly larger noise level.

[0110] In some examples, the stimuli are provided such that the first stimulus has a larger SPL than the second stimulus. Thereby, the circumstance may be favorably exploited that the first stimulus based on processing of radio audio signal B is hardly perceptible in the environment when only produced inside the ear canal, wherein the second stimulus based on a processing of ambient audio signal A requires a sound emission by external sound source 145 in the environment, which can be increasingly disturbing for people in the environment with an increasingly larger SPL of the second stimulus.

[0111] In some implementations, when multiple stimuli are provided, at least one of the stimuli is based on a processing of ambient audio signal A, corresponding to operation S42, so as to perform the REM in an environment more similar to a natural listening environment and / or to perform the REM in a scenario in which components and / or features and / or properties of the hearing device are applied which are not employed for a stimulus based on a processing of radio audio signal B.

[0112] In some implementations, a third stimulus is produced in another operation subsequent to operation S42. In the subsequent operation, after receiving radio audio signal B, first variant 131, 132 of the second operational mode is executed again for obtaining output audio signal O so as to provide the first stimulus. In some examples, the stimuli are provided such that the first stimulus has a smaller SPL than the second stimulus, and the third stimulus has a larger SPL than the first and second stimulus.

[0113] While the principles of the disclosure have been described above in connection with specific devices, systems and methods, it is to be clearly understood that this description is made only by way of example and not as limitation on the scope of the invention. The above described preferred embodiments are intended to illustrate the principles of the invention, but not to limit the scope of the invention. Various other embodiments and modifications to those preferred embodiments may be made by those skilled in the art without departing from the scope of the present invention that is solely defined by the claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single processor or controller or other unit may fulfil the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.

Claims

1. A hearing device configured to be at least partially inserted into an ear canal of a user, the hearing device comprising - an audio input unit (113) for obtaining an input audio signal (A, B), the audio input unit comprising a radio receiver (125) configured to receive a radio audio signal (B) from a remote audio source via radio frequency (RF) radiation; - a processing unit (115) for audio signal processing of the input audio signal (A, B) to obtain an output audio signal (O); and - an audio output unit (119) for outputting sound based on the output audio signal (O), wherein, in a first operational mode for providing the outputted sound so as to compensate for a hearing loss of the user, the audio signal processing comprises - amplifying, in an amplification operation, the input audio signal (A, B) according to a transfer function, characterized in that, in a second operational mode for providing the outputted sound as a stimulus for performing a real ear measurement (REM), the processing unit (115) is configured to perform the audio signal processing by processing the radio audio signal (B) as the input audio signal, wherein the audio signal processing comprises said amplification operation.

2. The hearing device of any of the preceding claims, wherein the audio input unit (113) further comprises a sound detector (123) configured to detect sound in an ambient environment of the user and to provide an ambient audio signal (A) representative of the detected sound, wherein, in the first operational mode, the processing unit (115) is configured to perform the audio signal processing by processing the ambient audio signal (A) and / or the radio audio signal (B) as the input audio signal.

3. The hearing device of claim 2, wherein, in the second operational mode, the processing unit (115) is configured to perform the audio signal processing so as to provide for different stimuli comprising a first stimulus, for which the audio signal processing is performed by processing the radio audio signal (B) as the input audio signal, and a second stimulus, for which the audio signal processing is performed by processing the ambient audio signal (A) as the input audio signal.

4. The hearing device of any of the preceding claims, wherein in the second operational mode, the audio signal processing comprises, in addition to said amplification operation, - modifying, in a stimulus preparation operation, a property of the input audio signal (A, B) so as to provide for a modified input audio signal (M) adapted for conditions required for the real ear measurement (REM).

5. The hearing device of claim 4, wherein the property of the input audio signal comprises at least one of - a sound pressure level (SPL) represented by the input audio signal (A, B); - a range and / or shape of a frequency spectrum included in the input audio signal (A, B); and - a vocal effort represented by the input audio signal (A, B).

6. The hearing device of claim 3 and claim 4 or 5, wherein, during said modifying of the property of the input audio signal (A, B), the processing unit (115) is configured to provide for a different sound pressure level (SPL) represented by the modified input audio signal (M) when providing the first stimulus as compared to when providing the second stimulus.

7. The hearing device of claim 6, wherein the processing unit (115) is configured to provide for a lower sound pressure level (SPL) represented by the modified input audio signal (M) when providing the first stimulus as compared to when providing the second stimulus.

8. The hearing device of claim 7, wherein, when providing the first stimulus, the sound pressure level (SPL) represented by the modified input audio signal (M) is at most 60 dB.

9. The hearing device of claim 3 and any of claims 4 to 8, wherein the different stimuli comprise a third stimulus and, during said modifying of the property of the input audio signal (A, B), the processing unit (115) is configured to provide for a higher sound pressure level (SPL) represented by the modified input audio signal (M) when providing the third stimulus as compared to when providing the first and second stimulus.

10. The hearing device of claim 9, wherein, when providing the third stimulus, the audio signal processing is performed by processing the radio audio signal (B) as the input audio signal.

11. The hearing device of any of claims 3 to 10, wherein, in a calibration operation for calibrating the stimulus provided in the second operational mode, the processing unit (115) is configured to - compare the ambient audio signal (A) to a reference quantity (C) indicative of one or more properties of the ambient audio signal (A) required for providing the stimulus; and - adjust, based on the comparison, one or more processing parameters applied in said stimulus preparation operation when processing the ambient audio signal (A) as the input audio signal.

12. The hearing device of claim 11, wherein the radio receiver (125) is configured to obtain the reference quantity (C) via radio frequency (RF) radiation.

13. The hearing device of any of the preceding claims, further comprising - an ear-canal microphone (219) configured to provide an in-the-ear audio signal (I) indicative of a sound detected inside the ear canal, wherein, in the second operational mode, the processing unit (115) is configured to evaluate the in-the-ear audio signal (I) so as to obtain an output data signal (R) indicative of at least one parameter determined in the real ear measurement (REM).

14. The hearing device of claim 13, further comprising - a probe tube (235) attachable to the ear-canal microphone (219).

15. A method of operating a hearing device configured to be at least partially inserted into an ear canal of a user, the hearing device comprising - an audio input unit (113) for obtaining an input audio signal (A, B), the audio input unit comprising a radio receiver (125) configured to receive a radio audio signal (B) from a remote audio source via radio frequency (RF) radiation; - a processing unit (115); and - an audio output unit (119) for outputting sound based on the output audio signal (O), the method comprising - performing, by the processing unit (115), audio signal processing of the input audio signal (A, B) to obtain an output audio signal (O), wherein, in a first operational mode for providing the outputted sound so as to compensate for a hearing loss of the user, the audio signal processing comprises - amplifying, in an amplification operation, the input audio signal (A, B) according to a transfer function, characterized by, in a second operational mode for providing the outputted sound as a stimulus for performing a real ear measurement (REM), - performing the audio signal processing by processing the radio audio signal (B) as the input audio signal, wherein the audio signal processing comprises said amplification operation.

Images