Directional signal processing method for a hearing instrument

Abstract

The invention relates to a directional signal processing method for a hearing instrument (1), wherein a first input signal (E1) is generated from an ambient sound (2) by a first input transducer (M1) of the hearing instrument (1), and a second input signal (E2) is generated from the ambient sound (2) by a second input transducer (M2) of the hearing instrument (1). The angular direction (α) of a sound source (16, 17) relative to a first reference direction (R1), in particular relative to a frontal direction (12) of the wearer (10) of the hearing instrument (1), is at least approximately detected on the basis of the first input signal (E1) and the second input signal (E2), and the orientation direction (vw1, vw2) of the sound source (16, 18), in particular relative to a second reference direction (R2), is at least approximately detected on the basis of the first input signal (E1) and the second input signal (E2). The contribution of a sound signal of the sound source (16, 18) to a processing signal generated using the first input signal (E1) and the second input signal (E2) is increased or decreased on the basis of the detected angular direction (α) and the detected orientation direction (vw1, vw2) of the sound source (16, 12).

Description

[0001] Description

[0002] Method for directional signal processing for a hearing instrument

[0003] The invention relates to a method for directional signal processing for a hearing instrument, wherein, based on a first input signal and a second input signal of the hearing instrument, an angular direction of a sound source relative to a frontal direction of a wearer of the hearing instrument is at least approximately recognized, and the input signals are processed depending on this angular direction.

[0004] In hearing instruments, particularly hearing aids in the narrower sense, an input signal is processed into an output signal, primarily through frequency-band-specific signal processing, and delivered to the ear of the hearing instrument's wearer, for example, via a loudspeaker. This signal processing can also be specifically tailored to the wearer and, in particular, their audiological requirements, such as in hearing aids designed to address the wearer's hearing impairment.

[0005] The aforementioned signal processing is often also directional in the sense that several input signals are processed into the output signal in such a way that sound from different spatial directions of the environment enters the output signal differently, i.e., sound from some spatial directions is suppressed, and sound from other spatial directions is amplified.

[0006] For this type of directional microphone technique, signal processing is usually based on specific models of the environmental situation. For example, a sound source located in the frontal direction of the user is generally considered relevant or a useful signal source, since it is assumed that the user will focus their gaze on the sound sources relevant to them. Another assumption is, for example, that noises from the rear hemisphere of the user, possibly depending on their spectrum, are generally interpreted as background noise.

[0007] Especially in complex conversations with multiple participants, and particularly in environments with a lot of background noise (e.g., in a restaurant, a so-called "cocktail party" listening situation), this type of signal processing reaches its limits, as the differentiation between relevant and irrelevant sound signals is often too crude or imprecise. However, such differentiation is crucial in these complex listening environments to allow the user to clearly distinguish specific conversation partners from background noise and / or other speakers (who might be involved in other conversations, i.e., without the user).

[0008] The invention is therefore based on the objective of providing a method by which an additional possibility is provided for a hearing instrument to process sound sources differently depending on their relevance to a wearer of the hearing instrument.

[0009] The aforementioned problem is solved according to the invention by a method for directional signal processing for a hearing instrument, wherein a first input signal is generated from ambient sound by a first input transducer of the hearing instrument, and a second input signal is generated from ambient sound by a second input transducer of the hearing instrument, wherein, based on the first input signal and the second input signal, an angular direction of a sound source relative to a first reference direction, in particular to a frontal direction of a wearer of the hearing instrument, is recognized at least approximately, and wherein, based on the first input signal and the second input signal, an orientation direction of said sound source, in particular relative to a second reference direction, is recognized at least approximately.The method provides that, depending on the detected angular direction and orientation of the sound source, the contribution of a sound signal from the sound source is increased or decreased in a processing signal, which is generated based on the first and second input signals. Advantageous and, in some cases, inventive embodiments are the subject of the dependent claims and the following description.

[0010] A hearing instrument, in this context, generally encompasses any device designed to generate an electrical input signal from ambient sound by means of at least one, in particular, acousto-electrical input transducer; to process said input signal into an output signal by means of, in particular, frequency-band-specific amplification and / or compression; and to generate an audible signal from the output signal and deliver it to the ear of a wearer of this device, in particular by means of an electro-acoustic output transducer (e.g., a loudspeaker, a so-called balanced metal case receiver, or even a bone conduction receiver). Hearing instruments thus include, in particular, headphones (e.g., earbuds), headsets, smart glasses with loudspeakers, etc., which are equipped with a corresponding input transducer.However, a hearing instrument also includes a hearing aid in the narrower sense, i.e., a device for treating a hearing impairment of the wearer, in which, during the processing of the input signal to the output signal, the former is amplified and / or compressed, particularly depending on the frequency band, in order to compensate for the wearer's hearing impairment at least partially by means of an output sound signal generated from the output signal in a user-specific manner.

[0011] In particular, the hearing instrument can also be designed as a binaural hearing system with a first local device and a second local device, in which case the hearing instrument may preferably also have (at least) two further input transducers, wherein the first and second input transducers are arranged in the first local device, and the two further input transducers are arranged in the second local device. The applicability of the described method is generally independent of this.

[0012] A first or second input converter, in this context, includes in particular any device designed to generate a corresponding electrical signal from an acoustic signal. In particular, the generation of the first or second input signal by the respective input converter may also involve preprocessing, e.g., in the form of linear pre-amplification and / or analog-to-digital conversion. The input signal generated is, in particular, an electrical signal whose current and / or voltage fluctuations essentially represent the sound pressure fluctuations in the air.

[0013] The angular direction of a sound source relative to the wearer's frontal direction is understood to mean, in particular, that by wearing the hearing aid as intended on the head (also in the case of a binaural hearing system as a hearing aid), especially on or in one ear (in the case of a monaural hearing aid), a clear relationship is established between the two input transducers and the wearer's frontal direction. By means of appropriate directional processing of the two input signals, it is thus possible to determine, for example via time-of-arrival differences of corresponding signal components in the first and second input signals, the angular direction in which a sound source is positioned. This angle is referenced to the first reference direction, which is itself given by, or can be defined based on, the described frontal direction.

[0014] The orientation direction of a sound source is understood here to be, in particular, the direction in which the sound source emits its maximum sound energy, or in which the emission maximum of the sound energy of the sound source lies. In the case of a speaker as the sound source, this direction is normally equivalent to the speaker's frontal orientation. In the case of a loudspeaker, the orientation direction is usually defined by an axis of symmetry of the diaphragm arrangement (or diaphragms). The orientation direction can be specifically related to the first reference direction, preferably the frontal orientation of the person wearing the hearing instrument, as a vectorial direction (i.e., shifted towards the sound source), such that the vectors of the first and second reference directions are parallel. Preferably, however, the second reference direction is defined by the aforementioned angular direction.However, due to the fixed relationship between the first and second reference directions, the definition of the second reference direction can preferably be chosen depending on a subsequent application, since all alternative definitions are equivalent to each other (except for a corresponding angular transformation).

[0015] Approximate recognition of the angular direction and / or orientation direction includes, in particular, specifying a plurality of at least three (and preferably more) discrete angle values ​​as a possible range of values ​​for the respective direction, determining the angle value that most closely corresponds to the actual angular direction or orientation direction, and outputting the angle value as the recognized angular direction or orientation direction.

[0016] In this context, at least approximate recognition means that the recognition of the respective direction can take place either in the aforementioned discrete angle values ​​or continuously and, in particular, exactly (within the scope of the respective possibilities, which are determined in particular by any effects of discretization, sampling rates and finite computing and storage capacities, etc.).

[0017] The detection of the angle or orientation direction based on the first and second input signals particularly includes performing the detection directly on the signal components of the first and second input signals, i.e., applying a corresponding angle-dependent filter (e.g., a notch filter) directly to the first and second input signals to detect the direction in question, and / or determining a propagation delay difference of signal components directly in the first and second input signals. Preferably, such a filter can also take into account the shadowing effect of the head, in particular by means of one or more head-related transfer functions, especially those dependent on the direction of orientation.

[0018] However, the detection of the angle or orientation direction based on the first and second input signals also includes applying the filter used to detect the direction to a first intermediate signal and a second intermediate signal, and / or determining the propagation delay difference of signal contributions in the first and second intermediate signals. The first intermediate signal is preferably derived solely from the first input signal (i.e., without signal contributions from the second input signal being directly incorporated into the second intermediate signal), and the second intermediate signal is preferably derived directly from the second input signal (i.e., preferably without signal contributions from the first input signal being incorporated into the second intermediate signal).

[0019] The intermediate signals can be generated from the respective input signals using single-channel preprocessing. Alternatively, the intermediate signals can be generated from the first and second input signals using directional preprocessing, for example, as forward and reverse cardioid signals.

[0020] The detection of the angular direction of the sound source can precede the detection of the orientation direction, or occur together with it.

[0021] By identifying the orientation of the sound source, which also includes the direction of maximum sound energy emission, and its relation to the angular direction, it becomes easier to distinguish whether the sound source is a source of unwanted noise or a potential source of useful signal for the wearer. Specifically, a sound source can be interpreted as a source of unwanted noise if, due to its orientation (given a specific angular direction), only a small portion of the sound energy is emitted towards the wearer of the hearing instrument. This can be differentiated, for example, using appropriate angular thresholds originating from the sound source.For example, contributions from a sound source whose orientation is directed towards the carrier can generally be increased, or contributions from a sound source whose orientation is directed sufficiently away from the carrier (e.g. at least at a right angle with respect to the angular direction) can be reduced even if the sound source (e.g. a speaker) is located in front of the carrier (i.e. in the frontal direction or in an angular range of preferably ± 60°, particularly preferably ± 45°, around the frontal direction).

[0022] Preferably, the sound source is identified as relevant to the user based on its orientation, and its contribution to the processing signal is increased. This can be done in conjunction with speech recognition (e.g., using spectral features such as formants and / or temporal features such as characteristic pauses in the input signals), so that the sound source is recognized as a speaker, and thus the relevant sound source is identified as a conversation partner of the user.

[0023] The detection of a relevant sound source can also be achieved using appropriate angular thresholds (originating from the sound source). For example, it can be checked whether the orientation direction, relative to the angular direction (i.e., the, preferably inverse, angular direction of the sound source as a second reference direction), is greater than, for example, ±10°, ±22.5°, or ±45° (i.e., whether the magnitude of the deviation of the orientation direction from the angular direction is greater than 10°, 22.5°, or 45°, respectively). If this is not the case for the set threshold, and the deviation is therefore smaller, the sound source is assumed to be essentially directed towards the wearer of the hearing system and is classified as a relevant sound source for the wearer.

[0024] Advantageously, the contribution of the sound signal from the relevant sound source to the processing signal is increased by generating a directional signal (e.g., a first directional signal) with a corresponding central direction (e.g., a first central direction) based on the first and second input signals. This central direction is oriented away from the angular direction towards the orientation direction of the sound source, and the aforementioned directional signal is then incorporated into the processing signal. Specifically, the processing signal is incorporated into the aforementioned output signal, so that its contributions (possibly amplified and / or compressed depending on the frequency) are also converted into the output sound.

[0025] This means, in particular, that the first input signal and the second input signal (or their respective derived, "unmixed" intermediate signals) are processed into a (first) directional signal using directional microphones. This directional signal has a (first) central direction, which is preferably determined by the direction of maximum sensitivity of its directional characteristic. The directional signal is generated in such a way (i.e., via directional parameters for superimposing the input signals and / or delays for direction-dependent interference) that its central direction does not correspond to the angular direction (and thus the directional signal is not directed exactly towards the sound source), but is slightly offset from the angular direction, specifically towards the orientation direction.

[0026] This is schematically illustrated by Figure 1, which shows a top view of a hearing situation of a wearer 10 of a hearing aid 1. The hearing aid 1 is a binaural hearing system with a first local device 1a and a second local device 1b, each of which has at least one input transducer (not shown). The arrangement of the two input transducers in the hearing aid 1 allows a first reference direction R1 to be defined for the intended use of the hearing aid 1, i.e., for wearing the respective local device 1a, 1b on the corresponding ear. This reference direction is preferably chosen in a frontal direction 12 of the wearer 10.

[0027] In an angular direction 'a' with respect to the first reference direction R1, which in this case is given by 'a' ≤ 15° and is defined by a speaker S1. The sound source 16 has an orientation direction vw1 in which the maximum of its sound energy is emitted. For the speaker S1 as the sound source 16, this orientation direction vw1 is synonymous with the speaking or looking direction of the speaker S1. The orientation direction vw1 is preferably defined relative to a suitably chosen second reference direction R2. In this case, the second reference direction R2 is chosen as the (reverse) angular direction 'a' of the speaker S1, but can in particular also be chosen to be identical to the first reference direction R1.

[0028] Due to the relatively frontal position (i.e., angular direction a) of speaker S1 and their orientation vw1, which is not significantly deviated from angular direction a (with vw1 at 45° with respect to R2), speaker S1 can be recognized as a relevant sound source for the carrier and thus as a conversation partner. Accordingly, a first directional signal D1 (directional signals are to be represented in spatial representations here and in the following by their respective directional characteristics) is generated such that it has a first central direction C1, which is slightly offset from the angular direction a of the sound source 16 (i.e., speaker S1) towards the orientation direction vw1. The first central direction C1 is the direction of maximum sensitivity of the first directional signal D1 or its directional characteristic.

[0029] In a further advantageous embodiment, a directional signal (e.g., a second directional signal) is additionally or alternatively generated based on the first and second input signals, and the contribution of the sound signal from the relevant sound source in the processing signal is increased by widening the directional characteristic, in particular a directional cone or similar, of said directional signal compared to an angularly oriented reference characteristic if the angular direction does not correspond to the orientation direction. This directional signal is then fed into the processing signal, which in turn preferably feeds into the output signal.

[0030] This can include, in particular, processing the first input signal and the second input signal (or derived, "unmixed" intermediate signals) into a (second) directional signal using directional microphones. This second directional signal has a (second) central direction. Conventional signal processing would then align this central direction angularly, i.e., directly towards the sound source. This conventional signal processing provides a reference characteristic (with a central direction angularly aligned directly towards the sound source) with a defined spread (which can depend, in particular, on the directionality and sound level of the sound signal from the sound source). The resulting (second) directional signal then spreads the directional characteristic compared to the reference characteristic, allowing a greater contribution from the sound source to be incorporated into the processed signal.

[0031] In particular, the directional characteristic of the aforementioned directional signal is asymmetrically widened, with a greater widening towards the orientation direction. This is schematically illustrated by Figure 2, which again shows the same listening situation of the wearer 10 of the hearing instrument 1 as shown in Figure 1 in a top view. In the present situation, conventional signal processing, i.e., signal processing without considering the orientation direction vw1 of the sound source 16, ceteris paribus, would generate a reference directional signal with a reference characteristic Dr (dashed line).

[0032] However, considering the orientation direction vw1, it can be concluded that the majority of the speaker S1's sound is emitted to the left of the angular direction a. Therefore, it is advantageous to generate a second directional signal D2 (solid line) whose directional characteristic exhibits an asymmetrical widening in the direction of orientation vw1 compared to the reference characteristic Dr. At the boundary of the second directional signal D2 facing away from orientation vw1 (this boundary could, for example, be defined by a specific degree of attenuation, such as 3 dB or 6 dB, relative to the maximum sensitivity), the second directional signal D2 can also run along the reference characteristic Dr. In particular, the widening described here allows the central direction (not shown) of the second directional signal Dr to be shifted towards orientation vw1, analogous to Figure 1.In a further advantageous embodiment, a plurality of scanning directional signals are generated based on the first and second input signals, each exhibiting a different central direction. The contribution of the sound signal from the relevant sound source in the processing signal is increased by generating a directional signal (e.g., a third directional signal) with a corresponding central direction (e.g., a third central direction) through a weighted superposition of at least some of the scanning directional signals. This central direction is oriented away from the angular direction and towards the orientation direction of the sound source. This directional signal is then fed into the processing signal, which in turn preferably feeds into the output signal.

[0033] This includes, in particular, processing the first and second input signals (or derived, "unmixed" intermediate signals) using directional microphones to create individual sampling directional signals, each oriented in different directions (i.e., exhibiting different central directions), thus "scanning" at least a portion of the room (whereby the portion preferably includes at least the sound source). A (third) directional signal is then generated by weighted superposition of at least some of these sampling directional signals, the (third) central direction of which is oriented away from the angular direction towards the orientation direction of the sound source.

[0034] This is schematically illustrated by Figure 3, which shows a top view of the same listening situation of the wearer 10 of the hearing instrument 1 as shown in Figure 1. Here, at least three scanning directional signals Da1, Da2, Da3 (dashed lines) are generated for the detected angular direction a and orientation direction vw1 of the speaker S1, each with a different orientation, i.e., different central directions Ca1, Ca2, Ca3. In this example, these central directions Ca1, Ca2, Ca3 are given by Ca1 = 0°, Ca2 = 45°, Ca3 = 90°. This is intended to be only an example representation of the scanning directional signals Da1, Da2, Da3, so that other scanning directional signals can be used, and / or the central directions Ca1, Ca2, Ca3 of the scanning directional signals Da1, Da2, Da3 can have different angular distances (e.g., 30° each) from each other.Preferably, at least three scanning directional signals Da1, Da2, Da3 are used and / or scanning directional signals with an angular separation of < 90° with respect to adjacent central directions are used. The scanning directional signals Da1, Da2, Da3 are then superimposed, generating a third directional signal D3 (solid line), approximately of the form shown.

[0035] D3 = g1 ■ Da1 + g2 ■ Da2 + g3 ■ Da3 with weighting factors g1 , g2, g3 and g1 + g2 + g3 = 1 . The aforementioned superposition is designed such that the third directional signal D3 consequently has a third central direction C3, which is oriented away from the angular direction a towards the orientation direction vw1 of the sound source 16 (accordingly, g2 > g1 , g2 > g3 applies here).

[0036] Advantageously, to increase the contribution of the sound signal from the sound source to the processing signal, a frequency-dependent gain is also applied for an upper frequency range. Especially in cases where the orientation of the sound source does not coincide with the angular direction (and thus the sound source is not directly directed towards the wearer of the hearing instrument), such a spatial orientation results in only a small proportion of the sound signal reaching the wearer of the hearing instrument, particularly in higher frequency ranges from 1500 Hz, preferably 2000 Hz, due to the high directionality. If the sound source is a speaker (which is often the case), the loss of sound power in these frequency bands further impairs speech intelligibility for the wearer, since these frequency bands contain important formants for vowel recognition and characteristic energies of consonants.Therefore, temporarily increasing the gain in these frequency ranges can be advantageous, even if this might make the overall sound sharp or shrill, since the interest in good speech intelligibility likely outweighs that in achieving the most natural sound possible. It is also advantageous if the sound source is identified as irrelevant to the carrier based on its orientation, and its contribution to the processing signal is reduced. In principle, the above statements regarding the identification of a relevant sound source apply analogously to the identification of a sound source as irrelevant to the carrier (especially with regard to angular ranges, etc., which are then preferably to be interpreted by corresponding complementary ranges or similar). For example,A sound source located in front of the support (i.e., in the frontal direction or at an angle of preferably ± 60°, particularly preferably ± 45°, around the frontal direction) is interpreted as a sound source irrelevant to the support, and its contributions are reduced accordingly if its orientation direction is sufficiently away from the support (e.g., at least at a right angle to the angular direction, which preferably represents an orientation towards the support).

[0037] This can advantageously be achieved, in particular, by generating a plurality of sampling directional signals based on the first and second input signals, each having a different central direction, wherein the contribution of the sound signal from the irrelevant sound source in the processing signal is reduced by generating a directional signal with a central direction through a weighted superposition of at least some of the sampling directional signals such that said central direction is aligned away from the angular direction and orientation direction of the sound source, and wherein said directional signal is incorporated into the processing signal. Such a configuration can be particularly advantageous if the irrelevant sound source is one of several existing sound sources in the vicinity of the carrier, and its angular direction is comparatively small (e.g.,preferably < 90°, particularly preferably < 60° or even < 45°) to the angular direction of a sound source identified as relevant.

[0038] This is schematically illustrated in Figure 4, which shows a top view of a new listening situation for the user 10 of the hearing instrument 1 according to Figure 1. The speaker S1, who constitutes a relevant sound source 16 for the user 10 of the hearing instrument 1, has an angular direction α of -90° to the frontal direction 12 of the user. In such a case, directional signal processing algorithms often identify a sound source as irrelevant or as a source of interference and attenuate its signal contributions. However, the speaker S1 is oriented towards the user 10, i.e., its orientation direction vw1 coincides with the (inverse) angular direction α. ​​In this case, the speaker S1 is recognized as a relevant sound source, and its contributions in the processing signal are amplified in the manner described above.

[0039] However, in the vicinity of the carrier 10, there is another speaker S2 whose angular direction a = -45° to the frontal direction 12 of the carrier. Speaker S2 is not oriented towards the carrier 10; instead, his orientation vw2 is rotated 90° relative to the first reference direction R1 defined by his angular direction a. Speaker S2 is therefore participating in a conversation with different interlocutors (not shown) than the carrier and is thus to be classified as an irrelevant sound source 18.

[0040] In the comparatively complex situation shown in Figure 4, two sound sources 16 and 18 are located close to each other (the angular separation of their respective directions is only 45°). However, one sound source 16 (i.e., the speaker S1) is recognized as relevant to the carrier 10, while the other sound source 18 (i.e., the speaker S2) is recognized as irrelevant. In this case, the procedure described above is useful for reducing the contribution of the sound signal from the irrelevant sound source 18 in the processing signal. This is achieved by generating a third directional signal D3 with a third central direction C3 through a weighted superposition of at least some of the aforementioned sampling directional signals. This third central direction C3 is aligned away from the angular direction a and the orientation direction vw2 of the irrelevant sound source 18 and, as far as possible, towards the relevant sound source 16.

[0041] In particular, the contribution of the sound signal from the irrelevant sound source to the processing signal can also be reduced by generating a directional signal with an associated directional characteristic based on the first and second input signals. This directional characteristic exhibits a local minimum and preferably a global minimum near the angular direction relative to the orientation direction. This includes, in particular, that the local and preferably global minimum of the directional characteristic, which can preferably also completely eliminate the contribution of the sound signal from the irrelevant sound source, lies in a range of [0°, 6] with 6 < 15° and particularly preferably 6 < 10° from the angular direction a, where the direction (i.e., whether a + 5 or a - 5 is to be selected) is determined by the orientation direction.

[0042] Advantageously, it is determined whether the sound source lies in a first region located in the front hemisphere of the support, whereby the orientation of the sound source is only detected if the sound source lies in the first region. This prevents computing power from being wasted on detecting a relevant sound source when the sound source lies in a region of the space that is a priori considered irrelevant to the support. The first region can preferably be selected as the region [-67.5°, 67.5°], particularly preferably [-60°, 60°] with respect to the first reference direction or the frontal direction of the support.

[0043] Advantageously, the orientation direction is approximately detected by selecting from a plurality of, preferably at least three, discrete core orientation directions. The orientation direction can also be detected by identifying one of three orientation areas: orientation direction facing the carrier, orientation direction past the carrier in front, or orientation direction past the carrier at the rear. To determine whether a sound source is relevant to the carrier, a higher resolution, i.e., a larger range of values ​​for the orientation directions (with respect to the angular direction or the inverse angular direction), is often unnecessary. Therefore, more complex determination methods and, in particular, more complex calculations can be avoided.Advantageously, a plurality of angle-dependent and orientation-direction-dependent filters are provided, each corresponding to an orientation direction at a specific angular direction. These plurality of filters are applied to the first and second input signals and / or to a first and second intermediate signal, derived from the first and second input signals, respectively. From this, at least a set of corresponding orientation-direction-dependent features is determined, and the orientation direction is recognized based on these orientation-direction-dependent features. In particular, the filters, and thus also the resulting features, can depend on the respective angular direction.

[0044] The feature preferably used is the determination of a sound level or a degree of attenuation of sound from a sound source arranged in the relevant angular direction and aligned with the relevant orientation direction. The filters are particularly designed as notch filters, which are applied directly to the first and second input signals, or to a first and second intermediate signal derived from each of these, and effect corresponding spatial filtering with the relevant angular range and the associated orientation direction, so that maximum emphasis or maximum attenuation towards one of the orientation directions can be determined.

[0045] The orientation-direction-dependent filters "scan" the space around the sound source at a given angular direction, so that, in particular, the orientation direction associated with the relevant feature can be determined based on a maximum or minimum of the orientation-direction-dependent features.

[0046] Particularly preferred is the comparison of a reference signal, preferably with an omnidirectional directional characteristic, to determine the degree of attenuation. This comparison signal is generated by applying the filter to the first and second input signals and / or to the first and second intermediate signals. Such a comparison is particularly easy to implement, and the reference signal provides a benchmark for the overall sound level as a reference for the attenuation by the respective filter.

[0047] In particular, a two-stage detection process can be implemented by first determining the angular direction of a sound source (this determination can also be carried out in ways other than using filters, e.g., by means of interaural time / phase differences), and then providing a plurality of orientation-direction-dependent filters for the detected angular direction. However, the detection of the angular direction a and the orientation vw can also occur simultaneously by providing a plurality of discrete configurations, each defined by a pair (aj, vw-k), where the indices j and k indicate the different possible combinations of their respective angles. The corresponding filters are provided for each of these combinations, and the angular direction and orientation of the sound source are then detected based on their associated features.

[0048] This means, in particular, that only a specific number of possible configurations deemed relevant are checked, where each configuration is defined by one of several possible angular directions and an associated orientation (specifically, relative to the respective angular direction or inverse angular direction). For each angular direction, there can be exactly one or more orientations (i.e., one configuration or multiple configurations for that angular direction). This allows for minimal overhead by considering only a reduced number of configurations (compared to a potentially much larger number of possible configurations), providing appropriate filters, and determining the associated features.

[0049] It is further advantageous if, for each orientation direction to a given angular direction, an orientation-dependent head-related transfer function (ODHRTF) is provided, wherein each of the ODHRTFs represents a transmission path for sound from the sound source, which is arranged in a relevant angular direction with the said orientation direction, and wherein the orientation-dependent filters are formed based on the respective associated ODHRTF.

[0050] This means, in particular, that the respective filter, e.g., a notch filter, takes into account or preferentially incorporates the corresponding ODHRTF from the sound source (given a specific angle and orientation) to the first or second input transducer. This ensures a precise representation of the spatial propagation of the sound from the sound source to the respective input transducer, thus minimizing spatial distortion effects that could lead to an imprecise determination of the angle or orientation.

[0051] The ODHRTF represents an extension of the concept of the head-related transfer function (HRTF), which represents a transmission path for sound from a sound source arranged at a specific angle, but unlike the ODHRTF, does not depend on the orientation of the sound source. Preferably, the individual ODHRTFs are measured and / or simulated in a calibration beforehand (i.e., before the actual procedure).

[0052] The invention further describes a hearing instrument comprising a first input converter for generating a first input signal from ambient sound, a second input converter for generating a second input signal from the ambient sound, and a signal processing device, wherein the hearing instrument is configured to perform the aforementioned method, and wherein, in particular, the signal processing device is configured (by means of appropriate provision with processor power and addressable working memory, as well as by means of program instructions) to perform the signal processing steps of the aforementioned method and thereby generate the said processing signal.Preferably, the hearing instrument further comprises an output transducer for generating an output sound based on an output signal, wherein the signal processing device is configured to generate the output signal based on said processing signal.

[0053] The hearing instrument according to the invention shares the advantages of the method according to the invention. The advantages stated for the method and its further developments can be transferred analogously to the hearing instrument. The hearing instrument can, in particular, be a monaural, i.e., one-piece device, which is preferably worn by the user on one ear. In particular, the hearing instrument can also be a binaural hearing system with two local devices, each of which is worn on one or the other ear of the user.

[0054] An embodiment of the invention is explained in more detail below with reference to the drawings. The drawings schematically depict:

[0055] Fig. 1 shows a listening situation of a wearer of a hearing instrument with a nearly frontal conversation partner and a corresponding directional signal from the hearing instrument depending on the orientation direction of the conversation partner.

[0056] Fig. 2 shows the carrier in the listening situation according to Fig. 1 and a widening of a directional signal for better capture of speech contributions from the conversation partner,

[0057] Fig. 3 shows the carrier in the listening situation according to Fig. 1 and the generation of a directional signal for capturing speech contributions from the conversation partner using several predefined scanning directional signals.

[0058] Fig. 4 shows the wearer of the hearing instrument according to Fig. 1 in a listening situation with a conversation partner to the side and a speaker who is not relevant to him, and Fig. 5 shows a possible embodiment for the hearing instrument according to Fig. 1 in a block diagram.

[0059] Corresponding parts and sizes are marked with the same reference symbols in all figures.

[0060] Figure 5 schematically depicts a hearing instrument 1 in a block diagram, which in this case is a binaural hearing system 3 with a first local device 1a and a second local device 1b. The binaural hearing system 3 thus corresponds to the hearing instrument shown in Figures 1 to 4. The first local device 1a has a first input transducer M1, and the second local device 1b has a second input transducer M2. The first input transducer M1 and the second input transducer M2 are each provided by corresponding microphones. In particular, the first and / or second local device 1a, 1b can each have one or more additional microphones or other input transducers.

[0061] The first input transducer M1 is configured to generate a first input signal E1 from ambient sound 2 when the hearing instrument 1 is in operation. Similarly, the second input transducer M2 is configured to generate a second input signal E2 from ambient sound 2 when the hearing instrument 1 is in operation. The first input signal E1 and the second input signal E2 are fed to a signal processing unit 4 of the binaural hearing system 3, where both input signals E1 and E2 are processed into a first and a second output signal A1 and A2, respectively.

[0062] The signal processing device 4 comprises, in particular, a first signal processing unit 4a, which is arranged in the first local device 1a and directly receives the first input signal E1, and further comprises a second signal processing unit 4b, which is arranged in the second local device 1b and directly receives the second input signal E2. The second input signal E2 is also transmitted to the first local device 1a by means of appropriately provided and configured communication units (not shown), which are arranged in the first and second local devices 1a and 1b respectively (optionally with data compression), so that the second input signal E2 can be processed together with the first input signal E1 in the first signal processing unit 4a. Likewise, the first input signal E1 (optionally with data compression) can be processed in the first local device 1a.(under data compression) are transferred to the second local device 1b for processing there in the second signal processing unit 4b.

[0063] The processing of the first and second input signals E1, E2 to produce the first and second output signals A1, A2, respectively, involves, in particular, frequency band-specific amplification and / or compression. This signal processing of the two input signals E1, E2 to produce the first and second output signals A1, A2, respectively, is direction-dependent; that is, in ambient sound, contributions from individual sound sources originating from different directions can be amplified to varying degrees. Furthermore, this signal processing can be tailored to the audiological requirements of a user of the hearing aid 1.

[0064] The first local device 1a further comprises a first output converter L1, which is configured to generate a first output sound 6a from the first output signal A1. Similarly, the second local device 1b comprises a second output converter L2, which is configured to generate a second output sound 6b from the second output signal A2.

[0065] The schematic representation of the hearing instrument 1 in Figure 5 shows the respective local devices 1a, 1b as so-called behind-the-ear (BTE) hearing aids with an associated earpiece in which the respective output transducer L1 or L2 is arranged. However, the local devices 1a, 1b are also conceivable as other designs, in particular as in-the-ear (ITE) hearing aids, in-the-canal (ITC) hearing aids, completely-in-the-canal (CIC) hearing aids, receiver-in-the-canal (RIC) hearing aids, or especially as earphones not exclusively or primarily intended for the treatment of hearing loss. In particular, the hearing instrument 1 can also be designed as a monaural hearing aid in which the two input transducers M1, M2 are arranged. The applicability of the described method is generally independent of this.Although the invention has been illustrated and described in detail by the preferred embodiment, the invention is not limited by the disclosed examples and other variations can be derived by the person skilled in the art without leaving the scope of protection of the invention.

[0066] List of reference symbols

[0067] 1 hearing instrument

[0068] 1a / b first / second local device (of the hearing instrument)

[0069] 2 Ambient sound

[0070] 3 binaural hearing system

[0071] 4 Signal processing unit

[0072] 4a / b first / second signal processing unit

[0073] 6a / b first / second output sound

[0074] 10 carriers

[0075] 12 Frontal direction

[0076] 16 Sound source

[0077] A1 / 2 first / second output signal

[0078] C 1 / 2 / 3 first / second / third central direction

[0079] Ca1-3 Central direction (of a scanning directional signal)

[0080] D 1 / 2 / 3 first / second / third directional signal

[0081] Da1-3 sampling directional signal

[0082] Reference characteristic

[0083] E1 / E2 first / second input signal

[0084] L1 / 2 first / second output converter

[0085] M1 / 2 first / second input converter

[0086] R1 / 2 first / second reference direction

[0087] S1, S2 Speaker vw1, vw2 Orientation direction a Angle direction

Claims

Claims 1. Method for directional signal processing for a hearing instrument (1) , wherein a first input transducer (M1) of the hearing instrument (1) a first input signal (E1) is generated from an ambient sound (2), and a second input signal (E2) is generated from the ambient sound (2) by a second input transducer (M2) of the hearing instrument (1), wherein, based on the first input signal (E1) and the second input signal (E2), an angular direction (a) of a sound source (16, 17) relative to a first reference direction (R1), in particular to a frontal direction (12) of a carrier (10) of the hearing instrument (1), is detected at least approximately, wherein, based on the first input signal (E1) and the second input signal (E2), an orientation direction (vw1, vw2) of said sound source (16, 18), in particular relative to a second reference direction (R2), is detected at least approximately, and wherein, depending on the detected angular direction (a) and the detected orientation direction (vw1, vw2) of the sound source (16, 12) a contribution of a sound signal from the sound source (16,18) is raised or lowered in a processing signal which is generated based on the first input signal (E1) and the second input signal (E2).

2. Method according to claim 1, wherein the orientation direction (vw1 , vw2) of the sound source (16, 18) is recognized as a sound source (16) relevant to the carrier (10), and the contribution of the sound signal of the relevant sound source (16) in the processing signal is increased.

3. The method of claim 2, wherein the contribution of the sound signal of the relevant sound source (16) in the processing signal is increased by using the first A directional signal (D1-3) with an associated central direction (C1-3) is generated from the input signal (E1) and the second input signal (E2), which is directed away from the angular direction (a) towards the orientation direction (vw1) of the relevant sound source (16), and wherein the said directional signal (D1-3) is fed into the processing signal.

4. Method according to claim 2 or claim 3, wherein a directional signal (D1-3) is generated from the first input signal (E1) and the second input signal (E2), and wherein the contribution of the sound signal of the relevant sound source (16) in the processing signal is increased by widening a directional characteristic of said directional signal (D2) relative to a reference characteristic (Dr) oriented in the angular direction (a) when the angular direction (a) does not correspond to the orientation direction (vw1), and wherein said directional signal (D2) is fed into the processing signal.

5. Method according to claim 4, wherein the directional characteristic of said directional signal (D1-3) is asymmetrically widened, with a greater widening towards the orientation direction (vw1).

6. A method according to any one of claims 2 to 5, wherein a plurality of scanning directional signals (Da1-3) are generated based on the first input signal (E1) and the second input signal (E2), each having different central directions (Ca1-3), and wherein the contribution of the sound signal of the relevant sound source (16) in the processing signal is increased by generating a directional signal (D3) with an associated central direction (C3) by a weighted superposition of at least some of the scanning directional signals (Da1-3) such that said central direction (C3) points away from the angular direction (a) towards the orientation direction (vw1, vw2) of the relevant sound source (16). is aligned, and the directional signal is incorporated into the processing signal.

7. Method according to any one of claims 2 to 6, wherein an additional frequency-dependent gain is increased for an upper frequency range.

8. Method according to claim 1, wherein, based on the orientation direction (vw1 , vw2) of the sound source (16, 18), it is recognized as a sound source (18) irrelevant to the carrier (10), and the contribution of the sound signal of the irrelevant sound source (18) in the processing signal is reduced.

9. Method according to claim 8, wherein a first plurality of scanning directional signals (Da1-3) are generated based on the first input signal (E1) and the second input signal (E2), each having different central directions (Ca1-3), and wherein the contribution of the sound signal of the irrelevant sound source (18) in the processing signal is reduced by generating a directional signal (D3) with a central direction (C3) by a weighted superposition of at least some of the scanning directional signals (Da1-3) such that the said central direction (C3) is aligned away from the angular direction (a) and from the orientation direction (vw2) of the irrelevant sound source (18), and wherein the said directional signal is fed into the processing signal.

10. A method according to any of the preceding claims, wherein a plurality of angle-dependent and orientation-direction-dependent filters are provided, each corresponding to an orientation direction (vw1, vw2) at a specific angular direction (a), wherein said plurality of filters are each directed to the first and second input signals (E1, E2) and / or to a first and a second Intermediate signals are applied, which are derived from the first and second input signals (E1, E2), respectively, and at least a set of corresponding orientation-direction-dependent features are determined from these, and the orientation direction (vw1, vw2) is recognized based on the said orientation-direction-dependent features.

11. Method according to claim 10, wherein for each orientation direction (vw1 , vw2) to a given angular direction (a) a head-direction-related transfer function is provided, wherein each of the head-direction-related transfer functions represents a transmission path for sound from the sound source (16, 18) which is arranged in a relevant angular direction (a) with said orientation direction (vw1 , vw2), and wherein said filters are each formed on the basis of the respective head-direction-related transfer function.

12. Hearing instrument (1) comprising a first input transducer (M1) for generating a first input signal (E1) from an ambient sound (2), a second input transducer (M2) for generating a second input signal (E2) from the ambient sound (2), and a signal processing device (4), wherein the hearing instrument (1) is configured to perform the method according to one of the preceding claims.

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