Method for operating a hearing aid system

Abstract

A method is described for operating a hearing aid system (2) comprising two hearing aids (1), each assigned to a user's ear during normal operation, each having a microphone (4) for detecting ambient sound and a loudspeaker (8) for outputting output signals based on the detected ambient sound to a user's ear. A representative variable (SPr, SPI) for a movement of the eardrum assigned to the respective ear is detected by means of a sensor (12) assigned to the respective hearing aid (1). A combined variable is created from the two representative variables (SPr, SPI). Based on the value of the combined variable, distance information of a current area of ​​interest of the user to the user is inferred, and at least one signal processing setting for the hearing aids (1) is adapted depending on the distance information.

Description

[0001] The invention relates to a method for operating a hearing aid system. Furthermore, the invention relates to a hearing aid system and a hearing device for use in such a hearing aid system.

[0002] Hearing devices are typically used to output an audio signal to the wearer's ear. This output is achieved via an output transducer, usually acoustically through sound waves transmitted via a loudspeaker (also called a "receiver"). Such hearing devices are frequently used as assistive listening devices (or simply hearing aids). They typically include an acoustic input transducer (especially a microphone) and a signal processor. This processor is designed to process the input signal (also called the microphone signal) generated from the ambient sound by the input transducer, using at least one user-specific signal processing algorithm, in such a way as to at least partially compensate for the wearer's hearing loss.Particularly in the case of a hearing aid, the output transducer can be a loudspeaker, a bone conduction receiver, or a cochlear implant, all of which are designed to mechanically or electrically couple the sound signal into the wearer's ear. The term "hearing devices" also includes devices such as tinnitus maskers, headsets, headphones, and similar devices.

[0003] Typical designs of hearing devices, especially hearing aids, are behind-the-ear (BTE) and in-the-ear (ITE) devices. These terms refer to the intended wearing position. Behind-the-ear hearing devices have a (main) housing that is worn behind the ear. A distinction can be made between models whose speaker is located within this housing—sound is typically delivered to the ear via a sound tube placed in the ear canal—and models that have an external speaker positioned in the ear canal. In-the-ear hearing devices, on the other hand, have a housing that is worn in the ear or even entirely within the ear canal.

[0004] Depending on the degree of hearing loss, hearing aids, especially assistive listening devices, can be used individually or in pairs, meaning one for each ear. In the latter case, a so-called binaural fitting can also be used, in which the signal processing by the two hearing aids is coordinated. Information is exchanged between the two devices for this purpose. This has advantages, for example, regarding the spatial perception of sounds, due in part to a higher, usable information content, but also for the suppression of background noise.

[0005] For a user (wearer) of a hearing device, especially a hearing aid, focusing on a specific acoustic area of ​​interest, where sounds from other areas of the room are suppressed or at least dampened, is often practical or desirable. This allows many people to concentrate better on understanding the desired sounds, usually speech. However, this requires identifying the user's area of ​​interest. Attempts are made, for example, by determining the orientation of the head in order to deduce where the user is looking and thus infer the area of ​​interest. Usually, however, this only allows the direction to be determined, enabling, for example, the adjustment of the microphone's directional characteristics. The user's distance from the sound sources of interest is also important.

[0006] The invention is based on the objective of improving the adaptation of a signal processing system of a hearing aid system to a current usage setting.

[0007] This problem is solved according to the invention by the independent claims. Advantageous and partly inventive embodiments and further developments of the invention are set out in the dependent claims and the following description.

[0008] The method according to the invention serves to operate a hearing aid system. This hearing aid system comprises two hearing devices, each assigned to one ear of a user during intended operation. Each hearing device has a microphone for detecting ambient sound and a loudspeaker for outputting signals based on the detected ambient sound to the user's ear. According to the method, a movement, specifically a representative quantity of this movement, of the eardrum assigned to the respective ear is first detected by means of a sensor assigned to each hearing device. Thus, the sensor of the hearing device assigned to the right ear detects a movement of the eardrum of the right ear, and the sensor of the "left" hearing device detects a movement of the left eardrum.From these two measurements, each representative of the respective eardrum, a combined measurement is derived. Based on the value of this combined measurement, information about the distance between the user's current area of ​​interest and the user themselves is then inferred. Depending on this distance information, at least one signal processing setting for the hearing aids is then adjusted.

[0009] Preferably, the respective hearing device used is a hearing aid that is designed to supply the user's hearing with output signals based on the detected ambient sound and preferably adapted by signal processing.

[0010] The invention is based on the premise that a user of a hearing device, particularly a hearing aid, regularly directs their gaze, and especially their focus, towards the spatial area corresponding to their acoustic area of ​​interest. The acoustic area of ​​interest is, in particular, the area in which a sound source that the user wishes to listen to is located. For example, it can be assumed that the user normally looks at their conversation partner, thus focusing their gaze on the conversation partner (or, for example, on a television set). The invention further assumes that eye movements (especially parallel movements along a line connecting the two ears, i.e., horizontal movements of the eyes in a "normal" upright head posture) are also reflected in the ears, specifically the eardrums.The invention now uses this knowledge to infer a change in the direction of gaze from the information about an existing eardrum movement and from this in turn to a focus on a certain distance and / or direction, and to use this for an adjustment of the signal processing settings.

[0011] In a practical variant of the method, a microphone is used as a sensor. This microphone is preferably directed into the ear canal of the respective ear. This is advantageous because hearing aids already sometimes have microphones that, when worn as intended, are directed into the ear canal. A sound pressure level, in particular its temporal profile (especially in the form of a wave-like signal or signal waveform), or pressure (especially the pressure measured between the eardrum and the hearing aid, preferably its temporal profile) is used as a representative parameter. Optionally, only the voltage output by the microphone can be used as a representative parameter.In particular, the sound pressure level or pressure is derived from this voltage – optionally, however, it can already be provided by an evaluation circuit (especially an ASIC) of the microphone. Specifically, for the present method, sound pressure levels on the order of approximately 55 dBA (where "approximately" means, in particular, + / - 5 dBA) or pressure changes on the order of approximately 42 mPa (where "approximately" means, in particular, a tolerance range corresponding to the aforementioned tolerance range) are considered relevant and form the basis of the evaluation described in more detail below. Sound pressure levels on the order of greater than 70 dBA are expediently ignored.

[0012] In another variant of the method, an optical distance sensor (or range sensor) is used as a sensor – either alternatively or optionally in addition to the microphone. Specifically, this optical distance sensor is a laser rangefinder, for example, one featuring a VCSEL laser. This distance sensor is used to detect, as a representative quantity, the displacement (hereinafter also referred to as stroke or deflection) of the eardrum, and in particular its temporal profile (i.e., in the form of a wave-like signal or signal waveform). For the method described here and below, displacements corresponding to a sound pressure level of approximately 56 dBA and / or generating microphone voltages with an amplitude of 10 to 50 mV are preferably considered relevant and form the basis for the evaluation described in more detail below.

[0013] An optional ultrasound sensor is used to measure the deflection of the eardrum as a representative parameter. This sensor consists of an ultrasound transmitter and a receiver. The ultrasound transmitter can be the loudspeaker of the hearing aid system, and the receiver can optionally be the microphone directed into the ear canal. Specifically, the ultrasound sensor determines distance information by calculating a transfer function between an output signal from the ultrasound transmitter and an input signal detected by the receiver, and by measuring changes in the time-of-flight differences.

[0014] In an optional variant of the process, a vibration sensor is used as a sensor – either as an alternative or optionally in addition to the microphone and / or the distance sensor. The vibration sensor typically detects acceleration. From this, the deflection of the eardrum can be inferred in a standard technical manner, for example, through integration.

[0015] According to a convenient variant of the method, a signal from the respective sensor(s) or the representative value derived therefrom is filtered using a bandpass filter with a bandwidth of 15 to 50 Hz, preferably 20 to 45 Hz. This means that preferably only a frequency band of 15 to 50 Hz or 20 to 45 Hz is used for further evaluation. This is based on the understanding that eye movements used to align the gaze—also known as "saccades"—are usually accompanied by corresponding oscillations of the eardrum with a duration of approximately 30 to 50 ms.

[0016] According to a preferred method variant, the combined quantity is calculated by subtracting the representative quantities assigned to the two ears, or the computational quantities derived from them. Specifically, the combined quantity is calculated by subtracting the two representative quantities or computational quantities from each other. For example, the representative quantity for the left ear is always subtracted from the representative quantity for the right ear (or vice versa). Advantageously, this subtraction allows the determination of the difference between the movements of both eyes. This difference, in turn, reflects a focusing of the gaze. If the user, for example, directs their gaze toward an object at a short distance—for instance, the tip of their nose—both eyes, or more precisely, their axes of gaze, move toward each other.If, on the other hand, the user directs their gaze towards an object at a greater distance, e.g. greater than 10 meters, the gaze axes of both eyes are approximately parallel to each other - in both examples assuming that there is no strabismus.

[0017] It is expedient to define the directions of movement of the eardrums of both ears as being the same. This means that, for example, an inward movement of the right eardrum (i.e., towards the left ear) is defined as positive, and correspondingly, an outward movement of the left eardrum (i.e., away from the right ear) is also defined as positive (or vice versa).

[0018] According to another suitable method, the distance information to the current area of ​​interest is determined by comparing the combined value with at least one predefined threshold. In this case, a distinction is made between a near-field and a far-field area for the area of ​​interest. For example, the threshold is chosen (particularly based on empirical studies or through a kind of learning phase with the individual user) such that the boundary between the near-field and far-field areas lies at approximately 3 meters. If the combined value falls below the threshold, it is assumed that the current area of ​​interest is in the near field. Optionally, at least two thresholds are specified to differentiate between a near-field, a close-field, and a far-field area.The first limit value is chosen, for example, such that the nearest field area extends up to a distance of 1 meter from the user, the near field area from 1 to 3 meters and the far field area beyond that.

[0019] According to an advantageous variant of the method, the representative value of the respective sensor is evaluated over a predetermined period to determine the combined quantity. Specifically, a selection of up to five (at least three) extreme values ​​is taken from the respective representative value—particularly for calculating the respective computational value. Preferably, the predetermined period corresponds to the last of possibly several saccades, i.e., specifically the duration of this saccade. As described above, the duration of the period is therefore approximately 30 to 50 ms. The extreme values ​​are, in particular, peaks of the wave-like signal of the respective representative quantity, for example, peaks in the sound pressure level.This method variant is based on the observation that approximately five such extreme values ​​appear over the course of the respective representative quantity, each exhibiting a predetermined minimum value (in particular, a magnitude value; in the case of pressure, more than 30 mPa; the sound pressure level behaves accordingly). Optionally, only maxima or only minima are considered as extreme values. Preferably, however, (especially normalized) magnitudes of the maxima and minima are also used as extreme values. Preferably, at least the first three extreme values ​​are selected.

[0020] For example, the average of up to five extreme values ​​(e.g., from at least three selected values) is calculated and chosen as the calculation parameter. Alternatively, the highest value of these up to five extreme values ​​or a predefined alternative (e.g., the second highest, etc.) is used for further evaluation. Optionally, an extreme value specified according to the order of occurrence (e.g., the second or third extreme value) can also be used as the calculation parameter. Furthermore, the value at the centroid of the area under the curve between two zero crossings (which, for example, include the highest or second-highest extreme value) can also be used.

[0021] According to a preferred refinement of the aforementioned method, temporally corresponding extreme values ​​are selected for each ear, occurring within a time interval of less than 5 ms. Assuming that both eyes move at least approximately simultaneously when consciously stimulated by the brain, it can be assumed that within this 5 ms timeframe, the extreme values ​​also correspond to the same eye movement, and in particular, to the same oscillation period (e.g., the third deflection of the eardrum). Thus, the probability is advantageously increased that, when combining the representative quantities, movements corresponding to the eyes are also observed.

[0022] According to a suitable procedural variant, a change in the user's gaze direction is first determined, and distance information is only obtained if no change in gaze direction is detected for a period of at least 0.5 to 5 seconds, preferably up to 3 seconds. If no change in gaze direction is detected for this period, it can be assumed with a high degree of probability that the user has now focused their attention on the new area and will, at least with a high degree of probability, remain so.

[0023] Changes in gaze direction are preferably detected using an inertial sensor, an electro-oculography sensor, and / or by monitoring the movement of the eardrum. For example, the temporal progression of this representative measurement can reveal whether a (prolonged) eye movement is occurring, or possibly several movements occurring in quick succession.

[0024] According to a preferred method variant, the signal processing setting is selected such that a mode is recorded in which sounds originating from sound sources at different distances from the user are suppressed or emphasized, depending on the distance information. Thus, if the distance information indicates a short distance to the area of ​​interest, sounds from a sound source close to the user are not suppressed or are even emphasized, while sounds from more distant sound sources are suppressed or at least attenuated. Conversely, sounds from a greater distance are not suppressed or emphasized, and those from a closer distance are suppressed or attenuated, if the distance information indicates a greater distance to the area of ​​interest.

[0025] Advantageously, and preferably for the mode described above, a signal processing setting such as a directionality is modified. In particular, the directionality (especially a "directional beam") is set to a wide angle (i.e., a comparatively large opening angle, e.g., from 35 to 180 degrees) when the distance information indicates a short distance to the area of ​​interest. Alternatively, the directionality is set to a narrow angle (e.g., 15 to 25 degrees) when the distance information indicates a greater distance between the area of ​​interest and the user. Thus, the directionality is chosen to be narrower for greater distances between the area of ​​interest and the user than for shorter distances.Alternatively or additionally, both hearing devices are used as a binaural hearing system, and the signal processing is adjusted (i.e., the signal processing settings are adapted) by applying time delays to signals (or even just signal components) from the respective microphones in such a way that a kind of spatial directivity is generated, i.e., in particular, an amplification and / or suppression of components of a total signal from all microphones (in the time or frequency domain). Such signal processing is known to those skilled in the art, particularly from the field of binaural hearing devices. Furthermore, a sound source from the area of ​​interest can also be localized—again additionally or alternatively—for example, by detecting time differences at the microphones, especially those of the binaural hearing system, and its specific frequency spectrum can be amplified (or suppressed for a sound source outside the area of ​​interest).

[0026] If the distance information indicates that the area of ​​interest is close to the user, the signal processing setting is appropriately modified (selected or preset) to filter out (i.e., suppress or dampen) noise from behind the user. This is because, in such a case, it can be assumed that the user is engaged in a conversation and therefore background noise is undesirable.

[0027] A hearing device system according to the invention comprises two hearing devices, each assigned to one ear of a user during intended operation. Each hearing device, in turn, has a microphone (in particular the one described above) for detecting ambient sound and a loudspeaker (in particular the one described above) for outputting signals based on the detected ambient sound to one ear of the user. Furthermore, each hearing device has a sensor for detecting movement of the eardrum assigned to the respective ear, as well as a processor (in particular the signal processor mentioned above) configured to perform the method described above automatically or in interaction with the user.

[0028] In particular, the hearing device of the hearing device system described above according to the invention corresponds to the hearing device described above within the framework of the method.

[0029] Preferably, the hearing aid system, and in particular the individual hearing device, exhibits the same physical characteristics resulting from the method described above. Thus, in corresponding embodiments, the method and the hearing aid system also share the respective optional physical and procedural characteristics, as well as their advantages.

[0030] The conjunction “and / or” is to be understood here and in the following in particular as meaning that the features linked by means of this conjunction can be formed both jointly and as alternatives to each other.

[0031] An embodiment of the invention is explained in more detail below with reference to a drawing. The drawing shows: Fig. 1 in a schematic top view of a person using a hearing aid system, Fig. 2 in a schematic diagram of a hearing device of the hearing device system, and Fig. 3 A schematic flowchart of a procedure performed by the hearing aid system.

[0032] Corresponding parts and sizes are always marked with the same reference symbols in all figures.

[0033] In Fig. Figure 1 is a person, hereinafter referred to as the user, shown schematically from above. The user wears a hearing device 1 of a hearing aid system 2 in each ear. In the illustrated embodiment, the two hearing devices 1 serve as hearing aids for the user; that is, they are designed to detect ambient sounds, amplify and / or filter the ambient sounds as part of signal processing, and then transmit the processed sounds to the user's ears.

[0034] Each hearing device includes 1 as shown in Fig. Figure 2 shows at least one microphone 4, which, when worn as intended, is directed towards the user's surroundings. Furthermore, the hearing device 1 includes a signal processor 6, on which at least one signal processing algorithm is executed. For outputting the processed sounds to the user's ear, the hearing device 1 has a loudspeaker 8. Each hearing device 1 also has a communication interface 10, here in the form of a coil-shaped antenna, for communication with the other hearing device 1.

[0035] The hearing aid system 2 is also designed to estimate the distance of a spatial area of ​​interest of the user from the user themselves and to adjust the signal processing to this distance, i.e., adapt it. For this purpose, each hearing aid 1 has a sensor in the form of a microphone 12, which in its intended operating state - see below. Fig. 1 - is directed into the ear canal of the respective ear.

[0036] The hearing aid system 2 is now set up to perform a subsequent task based on Fig. 1 and Fig. The procedure described in Figure 3 is to be carried out automatically (or autonomously). In a first step S1, each of the two hearing devices 1 monitors, using its respective microphone 12, whether a sound event is present within the ear canal. For example, so-called otoacoustic emissions can occur, which can be detected by the microphone 12. However, each hearing device 1 also monitors the ear canal for sounds louder than the otoacoustic emissions, i.e., sounds with a higher sound pressure level. Furthermore, each hearing device 1 filters out frequencies below 15 Hz and above approximately 45 Hz from the microphone signal MS emitted by its respective microphone 12, thus allowing only the frequency range between 15 and 45 Hz to pass through.

[0037] In a second process step S2, a sound pressure level SPr for the right ear and a sound pressure level SPI for the left ear are derived from the respective microphone signal MS. These sound pressure levels SPr and SPI each represent a typical movement of the respective eardrum.

[0038] Signal processor 6 is now configured to infer eye movement from the eardrum movements detectable by the sound pressure levels SPr and SPI. Eye movement, particularly saccades, can also be detected by eardrum movement, especially oscillation. The eardrum typically moves initially to the same side ("ipsilateral") as the eye movement. This means that one eardrum always bulges outwards while the other collapses inwards – during horizontal eye movements (in the case of an upright head position) or movements parallel to a line connecting the two ears. The eardrum then oscillates for a duration of usually about 30 to 50 ms if the eyes remain at rest in the new position. The deflection of the eardrums, and thus the value of the sound pressure level SPr or SPI, is used to determine the eye movement.SPI can at least estimate the range of movement, i.e., in particular how many degrees the eyes move to the side.

[0039] To determine the new eye position or eye orientation, the signal processor 6, in a third process step S3, determines whether the eye movement is complete. For this purpose, the signal processor 6 considers the temporal profile of the respective sound pressure level SPr or SPI and checks whether, for a period of 0.5 to 5 s, specifically within 1 s, any significant changes of, for example, more than 20 dBA (especially around a moving average characteristic of a background noise level) occur or have occurred.

[0040] If this is the case, the signal processor 6 determines the beginning of the last saccade. This is typically recognizable by the onset of an oscillation in the respective sound pressure level SPr or SPI of greater than 20 dBA, but also a maximum of 70 dBA. Larger deviations are usually caused by other events. A saccade usually comprises approximately five extrema in the course of the respective sound pressure level SPr or SPI within a time window of up to 50 ms, each with an amplitude of more than 20 dBA. In the present embodiment, the signal processor 6 selects the extremum with the highest value, i.e., the greatest amplitude, for each ear and compares whether the two extrema occurred within a time window of 5 ms. If so, it is assumed that these extrema represent corresponding displacements of the eardrum.To simplify comparability and a subsequent step, the signs of the two sound pressure levels SPr and SPI are chosen such that a positive value is present for a deflection of the eardrum to the right (i.e., inwards for the left ear and outwards for the right ear) (or vice versa).

[0041] From the two extreme values, the signal processor 6 determines the angle of the eye movements using a user-defined comparison curve or table based on empirical (statistical) data. This allows the spatial direction in which the eyes are realigned to be determined relative to the so-called 0-degree gaze direction (also known as sagittal direction or neutral direction).

[0042] For the signal processing settings of signal processor 6, it is also important to know the distance to the user of their spatial area of ​​interest, on which they wish to focus acoustically. The procedure described here is based on the assumption that people typically direct and focus their gaze on the sound source of interest (and thus their spatial area of ​​interest), for example, on a conversation partner. Therefore, in a fourth process step S4, signal processor 6 determines a combined value from the two sound pressure levels SPr and SPI, specifically from their extreme values. To do this, the signal processor subtracts the extreme value of the sound pressure level SPr selected in process step S3 from the corresponding sound pressure level SPI.Since the respective extreme value corresponds at least roughly to the orientation (angle in relation to the 0-degree viewing direction) of a viewing axis Ar or Al assigned to the respective eye (cf. . Fig. 1) The difference between the two extreme values ​​can provide information about whether the user is using a near-field area (see below). Fig. 1: long dashed-dotted gaze axes Ar and Al (shown here together with a change in gaze direction to the left) or a far-field area (short dashed-dotted gaze axes Ar and Al (shown here together with a change in gaze direction to the right) is focused. The signal processor compares the combined value, i.e., the difference, with a limit value G, which represents a spatial boundary, e.g., at a distance of 3 m from the user.

[0043] If the difference is less than the limit value G, the signal processor 6, in one embodiment, adjusts the signal processing directionality to a wide opening angle of, for example, 40 degrees. If the difference is greater than the limit value G, the signal processor 6 concludes that the spatial area of ​​interest lies in the far field and narrows the opening angle (e.g., to 20 to 25 degrees) so that fewer background noises from areas adjacent to the sound source of interest are detected. Preferably, the signal processor also checks whether the difference is greater than a further limit value that applies to an area outside the far field, e.g., a distance of more than 7 meters from the user. If the difference exceeds this further limit value, no adjustment of the signal processing based on the area of ​​interest is made.

[0044] According to another variant of this embodiment, binaural signal processing of the signals from the microphones 4 of both hearing devices 1 is used as an alternative to directional processing. By applying corresponding time delays to the signals of the microphones 4, sounds from areas close to the user (if the difference is greater than the limit value G) are suppressed (or attenuated), or, if the difference is less than the limit value G, sounds from areas farther away from the user (i.e., in this embodiment, more than 3 meters away) are suppressed. Alternatively, instead of suppressing the sounds, sounds from the opposite area can also be amplified.

[0045] The above always refers to "the" signal processor 6. In principle, it is possible for each signal processor 6 to determine the assigned sound pressure level SPr or SPI as well as the corresponding extreme value. However, the comparison of the time of the respective extreme value and the processing within the fourth process step S4 then takes place – after the corresponding information has been transmitted to a hearing device serving as a "server" (this is determined, for example, by presets or specified during the coupling of both hearing devices 1) – by only one of the two signal processors 6. The setting for the directivity – which is usually binaural anyway – is then transmitted to the other hearing device 1 using known methods. It is also possible, and in one variant also provided for, that one hearing device 1 (e.g., the left one) is always designated as the server for this process.The other hearing device 1 then transmits the microphone signal MS to the "server hearing device," which then performs the entire evaluation according to process steps S2 to S4 and then simply transmits the directional settings back to the other hearing device 1. Other configurations are also possible and are known to those skilled in the art for efficient execution of the process and / or can be left to the discretion of those skilled in the art.

[0046] The subject matter of the invention is not limited to the embodiment described above. Rather, further embodiments of the invention can be derived by a person skilled in the art from the above description. Reference symbol list 1 hearing aid 2 Hearing aid system 4 microphones 6 Signal processor 8 speakers 10 Communication interface 12 microphones MS microphone signal SPr sound pressure level SPI sound pressure level Ar viewing axis All viewing axis G limit value S1-S4 Process step

Claims

[1] Method for operating a hearing aid system (2) comprising two hearing aids (1), each assigned to one ear of a user in normal operation, each with a microphone (4) for detecting ambient sound and a loudspeaker (8) for outputting output signals based on the detected ambient sound to one ear of a user, wherein according to the method - a representative quantity (SPr, SPI) for a movement of the eardrum assigned to the respective ear is detected by means of a sensor (12) assigned to each hearing device (1), - a combined size is created from the two representative sizes (SPr, SPI), - based on the value of the combined size, a conclusion is drawn about the distance information of a current area of ​​interest of the user to the user, and - depending on the distance information, at least one signal processing setting for the hearing devices (1) is adjusted. [2] Method according to claim 1, wherein a microphone (12) is used as the sensor and wherein a sound pressure level (SPr, SPI) and / or a pressure is used as the representative quantity. [3] Method according to claim 1 or 2, wherein an optical distance sensor or an ultrasonic sensor is used as the sensor and wherein a deflection of the eardrum is used as the representative quantity. [4] Method according to one of claims 1 to 3, wherein a vibration sensor is used as the sensor. [5] Method according to any one of claims 1 to 4, wherein a signal of the sensor (12), optionally the representative quantity (SPr, SPI), is filtered by means of a bandpass filter of 15 to 50 Hz, preferably of 20 to 45 Hz. [6] Method according to any one of claims 1 to 5, wherein the combined quantity is formed by a difference between the representative quantities (SPr, SPI) assigned to the two ears or computational quantities derived from them, in particular wherein the combined quantity is formed by subtracting the two representative quantities (SPr, SPI) or computational quantities from each other. [7] Method according to any one of claims 1 to 6, wherein the distance information to the current area of ​​interest is determined by comparing the combined quantity with at least one predetermined limit value (G), in particular wherein at least two limit values ​​are predetermined to distinguish between a nearest field area, a near field area and a far field area, preferably wherein the nearest field area is predetermined up to 1 meter, the near field area from 1 to 3 meters and the far field area from 3 meters. [8] Method according to any one of claims 1 to 7, wherein to determine the combined quantity the representative quantity (SPr, SPI) of the respective sensor (12) is evaluated over a predetermined past period, and wherein a selection of up to five extreme values ​​is taken from the respective representative quantity (SPr, SPI), in particular wherein the predetermined past period corresponds to one of possibly several saccades. [9] Method according to claim 8, wherein temporally corresponding extreme values ​​are selected for each ear, which are within a time interval of less than 5 milliseconds. [10] Method according to any one of claims 1 to 9, wherein a change in the user's gaze direction is determined and wherein the distance information is determined when no change in the gaze direction is detected for a period of at least 0.5 to 5 seconds, preferably up to 3 seconds. [11] Method according to claim 10, wherein the change in the direction of gaze is detected by means of an inertial sensor, an electro-oculography sensor and / or by means of a movement of the tympanic membrane. [12] Method according to any one of claims 1 to 11, wherein the signal processing setting is selected such that a mode is recorded in which noises originating from sound sources at different distances to the user are suppressed or emphasized depending on the distance information. [13] Method according to any one of claims 1 to 12, wherein a directional effect is changed as a signal processing setting, in particular wherein the directional effect is set to wide when the distance information indicates a small distance of the area of ​​interest, or is set to narrow when the distance information indicates a greater distance of the area of ​​interest to the user. [14] Method according to any one of claims 1 to 13, wherein the signal processing setting is changed when the distance information indicates a small distance to the area of ​​interest, such that noises from an area behind the user are filtered out. [15] Hearing device system (2) comprising two hearing devices (1) each assigned to one ear of a user in intended operation, each with a microphone (4) for detecting ambient sound and a loudspeaker (8) for outputting output signals based on the detected ambient sound to one ear of a user, as well as each with a sensor (12) for detecting movement of the eardrum assigned to the respective ear and with a processor (6) configured to perform a method according to any one of claims 1 to 14.

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