METHOD FOR OPERATING A HEARING AID AND HEARING AID

Abstract

A method for operating a hearing aid includes providing the hearing aid with an ANC unit having a feedforward unit outputting a feedforward signal for suppressing external interference noises penetrating from the outside into an auditory canal of a user of the hearing aid. The ANC unit has a feedback unit outputting a feedback signal for suppressing internal interference noises present inside the auditory canal. The hearing aid has a signal processing unit which has a settable amplification and which amplifies an input signal of the hearing aid and outputs it as an amplified signal. The feedback signal is used as a measure of the user's own voice, and the amplification of the signal processing unit is set depending on the feedback signal and thus also depending on the user's own voice. A hearing aid having a control unit for executing the method is also provided.

Claims

1. A method for operating a hearing aid, the method comprising: a) providing a hearing aid including a signal processing unit having a settable amplification, and an ANC unit having a feedforward unit and a feedback unit; b) using the feedforward unit to output a feedforward signal for suppressing external interference noises penetrating from outside into an auditory canal of a user of the hearing aid; c) using the feedback unit to output a feedback signal for suppressing internal interference noises present inside the auditory canal; d) using the settable amplification of the signal processing unit to amplify an input signal of the hearing aid and output an amplified signal; and e) using the feedback signal as a measure of the user's own voice and setting the amplification of the signal processing unit in dependence on the feedback signal and thus also in dependence on the user's own voice.

2. The method according to claim 1, which further comprises during the user's own speech activity, using the feedforward unit to suppress the external interference noises in such a way that predominantly the user's own voice is contained in the feedback signal, causing the amplification to then be set in dependence on the user's own voice.

3. The method according to claim 1, which further comprises reducing the amplification with a rising amplitude of the feedback signal.

4. The method according to claim 1, which further comprises differentiating between phases of the user's own speech activity and phases without the user's own speech activity based on the feedback signal, for carrying out a recognition of the user's own voice at the same time by using the ANC unit.

5. The method according to claim 1, which further comprises using the ANC unit in combination with the signal processing unit to form an OVP unit, and using the OVP unit to recognize the user's own voice based on the feedback signal of the feedback unit and to process the user's own voice by using the signal processing unit in dependence on the feedback signal.

6. The method according to claim 1, which further comprises setting the amplification in a frequency-dependent manner, only in frequency ranges in which the user's own voice lies.

7. The method according to claim 1, which further comprises: providing the feedback unit with an operating range only including frequencies up to a limiting frequency; and setting the amplification for frequencies above the limiting frequency in dependence on the feedback signal.

8. The method according to claim 1, which further comprises providing the hearing aid with an external microphone generating the input signal, and supplying the input signal to the feedforward unit to generate the feedforward signal.

9. The method according to claim 1, which further comprises providing the input signal as a first input signal, and providing the hearing aid with an internal microphone generating a second input signal being supplied to the feedback unit to generate the feedback signal.

10. The method according to claim 1, which further comprises providing the hearing aid with an earpiece to configure the hearing aid for closed care, and using the earpiece to close off the auditory canal during an intended use of the hearing aid.

11. The method according to claim 1, which further comprises providing the hearing aid with a receiver, and combining the amplified signal, the feedback signal and the feedforward signal with one another to form an output signal being output through the receiver.

12. The method according to claim 11, which further comprises providing the hearing aid with an auxiliary amplifier, and using the auxiliary amplifier to amplify the output signal before the output signal is output through the receiver.

13. A hearing aid, comprising a control unit configured to execute the method according to claim 1.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0042] FIG. 1 is a diagrammatic, plan view of a hearing aid; and

[0043] FIG. 2 is a schematic and block diagram of the hearing aid of FIG. 1 during use thereof as intended.

DETAILED DESCRIPTION OF THE INVENTION

[0044] Referring now to the figures of the drawings in detail and first, particularly, to FIG. 1 thereof, there is seen a hearing aid 2 having an earpiece 4, a receiver 6, an internal microphone 8, at least one, in this case two, external microphones 10, a housing 12, and a control unit 14. FIG. 2 shows the hearing aid 2 and its interconnection more precisely and in a different view in which, however, only one of the two external microphones 10 is shown. In addition, FIG. 2 shows an auditory canal 16 of a user of the hearing aid 2 as well as three paths P1, P2, P3, through which the user's own voice can enter the auditory canal 16. During an intended use of the hearing aid as shown, for example, in FIG. 2, the user wears the hearing aid 2 in or on the ear. In the hearing aid type shown herein, the user wears the housing 12 on the ear, more precisely behind the ear, and the earpiece 4 in the ear. The concepts described herein are also similarly applicable to other hearing aid types. A method for operating the hearing aid 2, especially during the intended use of the hearing aid 2, is also described hereinafter on the basis of FIGS. 1 and 2. In the present case, the control unit 14 is configured to execute the method.

[0045] The hearing aid 2 has an ANC unit 18, wherein ANC is understood to mean active noise suppression, which is also referred to as “active noise cancellation.” The ANC unit 18 has a feedforward unit 20, which outputs a feedforward signal ff, for suppressing external interference noises, which penetrate during the intended use through the external path P1 from the outside into the auditory canal 16, especially also past the earpiece 4. Furthermore, the ANC unit 18 has a feedback unit 22, which outputs a feedback signal fb, for suppressing internal interference noises which are present inside the auditory canal 16. Internal interference noises are in particular, for example, standing waves in the auditory canal 16 due to an occlusion and noises caused by the user himself or herself, so-called user's own noises, among these also the user's own voice, which is transmitted through the internal path P2 as structure-borne sound into the auditory canal 16. The feedback unit 22 is also referred to as an AOR unit, since it effectively carries out AOR, i.e., active occlusion reduction. The feedforward signal ff and the feedback signal fb are each also generally referred to as a correction signal fb, ff. Both correction signals fb, ff are electrical signals which are supplied to the receiver 6 and are thereby converted into sound. This sound is then so-called anti-sound, which entirely or partially extinguishes, i.e., suppresses, the interference noises upon superposition in the auditory canal 16. Noise suppression takes place solely acoustically in this case and in particular not on an electrical level.

[0046] Since the ANC unit 18 has both a feedforward unit 20 and also a feedback unit 22, the ANC unit 18 is also referred to as a hybrid ANC unit 18, which accordingly carries out hybrid ANC. Interference noises of different origins are suppressed in this case, namely, on one hand, internal interference noises and, on the other hand, external interference noises. The feedback unit 22 and the feedforward unit 20 are operated in parallel to one another, as can be seen from FIG. 2, and are each independent subunits of the ANC unit 18. In addition, the feedforward unit 20 and the feedback unit 22 receive input signals E1, E2 independent of one another and each output a separate correction signal fb, ff.

[0047] The hearing aid 2 is generally used to output noises to a user and especially to compensate for a hearing deficit of a hearing-impaired user. The hearing aid 2 has a signal processing unit 24, which has a settable amplification 26, i.e., an amplification unit having a settable amplification factor. The signal processing unit 24 amplifies an input signal E1 of the hearing aid 2 and outputs it as an amplified signal S. The input signal E1 is an electrical signal and is generated by using at least one of the external microphones 10. During the intended use of the hearing aid 2, the signal processing unit 24 and its settable amplification 26 implement its actual hearing aid functionality, namely a modification of the input signal E1 depending on an individual hearing profile, also audiogram, of the user.

[0048] The amplified signal S and also the two correction signals fb, ff are output through the receiver 6. The receiver 6 converts the amplified signal S and the two correction signals fb, ff into sound. The correction signals fb, ff have been generated by the ANC unit 18 in such a way that the associated sound signals are destructively superimposed in the auditory canal 16 with the interference noises, whereby the interference noises are suppressed.

[0049] The signal processing unit 24 and the ANC unit 18 are parts of the control unit 14 of the hearing aid 2 in the exemplary embodiment shown. The control unit 14 is integrated in this case in the housing 12 which, depending on the hearing aid type, is worn on or in the ear by the user during the intended use.

[0050] In the present case, the feedback signal fb is used as a measure of the user's own voice and the amplification 26 of the signal processing unit 24 is set depending on the feedback signal fb and thus also depending on the user's own voice, so that the input signal E1 is also amplified depending on the feedback signal fb and thus also depending on the user's own voice. Correspondingly, a signal path 28 is formed in the hearing aid 2, which leads from the feedback unit 22 to the signal processing unit 24 and through which the feedback signal fb is supplied directly in FIG. 2 to the signal processing unit 24 or in an alternative (not shown) a signal derived therefrom is supplied to the signal processing unit 24 to activate it accordingly depending on the feedback signal fb. The amplification 26 and the noise suppression by the ANC unit 18 are accordingly coupled to one another and thus synchronized, i.e., a change in operation of the ANC unit 18 is also used to change the operation of the signal processing unit 24. The signal processing unit 24 is accordingly activated indirectly or directly by the feedback unit 22, so that the amplification 26 is set depending on the feedback signal fb.

[0051] The mentioned setting of the amplification 26 depending on the feedback signal fb is based on the following consideration: on one hand, due to the hybrid ANC in the auditory canal 16, possible external interference noises are already entirely or at least partially suppressed by the feedforward unit 20, on the other hand, sound in the auditory canal 16 is recorded for the feedback unit 22 to carry out AOR. Since the external interference noises are now suppressed, predominantly or even exclusively internal interference noises are then recorded in the auditory canal 16. In phases of the user's own speech activity, i.e., as soon as the user speaks himself or herself, his or her own voice is emitted outward into the surroundings, on one hand, and is then regularly also contained in the input signal E1 and is transmitted as structure-borne sound into the auditory canal 16, on the other hand, and is then present there as internal interference noise. At the same time, the user's own voice possibly also enters the auditory canal 16 from the outside and is then additionally present as external interference noise. Therefore, three paths P1, P2, P3 exist in principle for the user's own voice into the auditory canal 16, as is recognizable in FIG. 2. Two of the paths P1, P2, P3 are acoustic paths P1, P2, namely once from the outside and once from the inside into the auditory canal 16. The third path P3 is mixed acoustic-electric, namely from the outside through the microphone 10 into the signal processing unit 24 and then through the receiver 6 into the auditory canal 16.

[0052] FIG. 2 shows by way of example an external signal Ext, for example, the user's own voice and/or one or more other ambient noises, and additionally noise N as an external interference noise. Both the external signal Ext and also the noise N are sound which enter the auditory canal 16 through the external path P1 past the earpiece 4 and/or through the path P3 through the signal processing unit 24.

[0053] Due to the suppression of external interference noises by the feedforward unit 20, it is presumed in the present case that the user's own voice now forms a significant component of the still remaining internal interference noises, so that the feedback signal fb is usable as a measure of the presence of the user's own voice or even as a measure of the volume (also: level or amplitude) of the user's own voice. This measure is now also actually used to control the signal processing unit 24, so that this is controlled as a result depending on the user's own voice, more precisely: so that the amplification 26 is set depending on the user's own voice. Therefore, the processing of the input signals E1 in the signal processing unit 24 is adapted deliberately and promptly in phases of the user's own speech activity and therefore the processing and ultimately the output of the user's own voice also. The user's own voice which enters the auditory canal 16 through the internal path P2 as internal interference noise is accordingly used to adapt the amplification 26 of the user's own voice in the acoustic-electric third path P3. In this way, the processing of the user's own voice is improved, in this case especially with the goal of achieving more natural perception of the user's own voice or at least outputting it in such a way that it is perceived as less annoying by the user. In order to achieve this, the feedforward unit 20, in the case of the user's own speech activity of the user, suppresses the external interference noises in such a way that predominantly the user's own voice is contained in the feedback signal fb, so that the amplification 26 is then set depending on the user's own voice. Overall, in phases of the user's own speech activity, the user's own voice is then suppressed in all three paths P1, P2, P3, namely in the acoustic paths P1, P2 by using the ANC unit 18 and synchronously thereto in the acoustic-electric path P3 by using the signal processing unit 24.

[0054] In the present case, the feedback signal fb has an amplitude and the amplification 26 is reduced with rising amplitude. The input signal E1 is thus amplified less in the case of a louder user's own voice and therefore the user's own voice in the input signal E1 is also, so that the perception of the user's own voice is potentially improved for the user. This has the result in this case that the ANC unit 18 sets the amplification 26 differently depending on whether or not the user speaks himself or herself. In phases of the user's own speech activity, the amplitude is greater than in phases without the user's own speech activity, for example, if only other interference noises, for example, noise N are present. In phases of the user's own speech activity, the amplification 26 is thus set lower than in phases without the user's own speech activity and therefore in phases of the user's own speech activity the volume of the user's own voice in the input signal E1 is deliberately reduced, while in phases without the user's own speech activity, a greater amplification 26 is set to implement the most optimum possible comprehensibility of noises from the surroundings.

[0055] As is clear from the previous statements, it is possible in principle due to the suppression of external interference noises by using the feedforward signal ff to then identify phases of the user's own speech activity on the basis of the feedback signal fb, for example, if the feedback signal fb exceeds a predefined threshold value. Therefore, in the exemplary embodiment shown, a differentiation is made between phases of the user's own speech activity and phases without the user's own speech activity on the basis of the feedback signal fb, more precisely on the basis of its amplitude, so that a user's own voice recognition is carried out at the same time by using the ANC unit 18. The ANC unit 18 is therefore used for the user's own voice detection and thus also represents an OVD unit, i.e., a user's own voice recognition unit, wherein OVD stands for “own voice detection.” In the present case, a phase of the user's own speech activity is assumed above a predefined threshold value for the amplitude and analogously a phase without the user's own speech activity is assumed below the threshold value.

[0056] It is also conceivable in principle to record the user's own voice, for example, by using a spatial filter or a directional microphone, i.e., to record sound deliberately from a certain direction and then to presume that due to the direction it is the user's own voice in this case. The user's own voice detection described herein represents an alternative in this regard. According to the solution described herein, the ANC unit 18 more or less fulfills a double function, namely, on one hand, active noise suppression and, on the other hand, the user's own voice detection. A separate OVD unit is therefore superfluous and is also not present in the exemplary embodiment shown.

[0057] The ANC unit 18, especially in its function as an OVD unit, is then used to set the amplification 26 in order to reduce it in phases of the user's own speech activity and thus to attenuate the input signal E1 and at least the user's own voice contained therein. In addition, in the embodiment shown herein, the ANC unit 18 in combination with the signal processing unit 24 forms an OVP unit (not explicitly shown), wherein OVP stands for “own voice processing.” The OVP unit recognizes, on one hand, the user's own voice on the basis of the feedback signal fb of the feedback unit 22 and, on the other hand, processes the user's own voice depending thereon by using the signal processing unit 24, since its amplification 26 is set depending on the feedback signal fb. A separate OVP unit is then no longer necessary and is also not present in the exemplary embodiment shown.

[0058] The amplification 26 is optionally set in a frequency-dependent manner, namely only in those frequency ranges in which the user's own voice lies. In this way, the user's own voice is deliberately modified in the input signal E1 with the goal of the most natural possible output of the user's own voice to the user.

[0059] In an optional embodiment, the feedback unit 22 has an operating range which only includes frequencies up to a limiting frequency, which is in particular predefined and is stored, for example, in a memory (not explicitly shown) of the hearing aid 2. The limiting frequency is, for example, 1 kHz. The amplification 26 is then also set depending on the feedback signal fb for frequencies above the limiting frequency. In other words: the control of the amplification 26 is not solely restricted in the present case to those ranges which are also acquired by the feedback unit 22. This is based on the consideration that speech in general is not restricted to low frequencies. However, an ANC unit 18 is typically only configured for such low frequencies, since most interference noise is to be expected in this case and in particular speech, above all an external voice, is in principle rather not considered to be interference noise and is also not necessarily to be suppressed. Especially in the case of the user's own voice, however, a suppression is desirable for more natural perception. The fact is therefore then utilized that in the case of an operating range up to a certain limiting frequency, for example, 1 kHz, at least parts of the user's own voice are still acquired by the feedback unit 22, so that the feedback signal fb is nonetheless usable as an adequate measure for the presence or the volume of the user's own voice and thus for the user's own voice detection. A suppression of the user's own voice then also takes place at those frequencies which include the user's own voice, but not by the operating range of the feedback unit 22, to achieve the most optimum possible processing of the user's own voice in the signal processing unit 24 and in this way to generate a more natural sound of the user's own voice.

[0060] As already indicated, the hearing aid 2 has at least one microphone 10, through the use of which the input signal E1 is generated. This microphone 10 is an external microphone in this case. The corresponding input signal E1 is supplied in the exemplary embodiment shown to both the signal processing unit 24 and also the feedforward unit 20. An “external” microphone 10 is understood as a microphone 10 which is positioned during the intended use of the hearing aid 2 in such a way that exclusively or predominantly sound from the surroundings of the user is recorded by the microphone 10. For this purpose, the external microphone 10 is generally oriented outward and typically also positioned outside the auditory canal 16 of the user, for example, as shown in FIG. 2. In one alternative (not shown), the input signal E1 for the feedforward unit 20 is generated by using another, additional microphone of the hearing aid 2, so that two input signals E1 are generated, one for the signal processing unit 24 and one for the feedforward unit 20.

[0061] The feedback unit 22 also receives an input signal E2, which is generated by using a microphone 8 of the hearing aid 2. However, the input signals E1, E2 for the feedforward unit 20 and the feedback unit 22 differ, since these units are to suppress different interference noises, so that the microphones 8, 10 are accordingly positioned differently. The above-described input signal E1 for the signal processing unit 24 and the feedforward unit 20 is then also referred to as the first input signal E1. The internal microphone 8 then generates a second input signal E2, which is supplied to the feedback unit 22 to generate the feedback signal fb. In contrast to an external microphone 10, an “internal” microphone 8 is understood as a microphone which is positioned during the intended use of the hearing aid 2 in such a way, for example, as shown in FIG. 2, that exclusively or predominantly sound from the auditory canal 16 of the user is recorded by the microphone 8. For this purpose, the internal microphone 8 is typically oriented inward and into the auditory canal 16 and/or positioned inside the auditory canal 16 of the user.

[0062] The boundary between “inside” and “outside” is defined in the present case by the earpiece 4 of the hearing aid 2, which is seated during the intended use in the auditory canal 16 and delimits a volume therein, which is then located on the inside and is delimited by the earpiece 4, the auditory canal wall, and the eardrum. This volume is indicated in FIG. 2 as the auditory canal 16. In contrast thereto, the surroundings are located on the other side of the earpiece 4, namely on the outside. The output of sound by the hearing aid 2 takes place toward the inside in both cases, thus into the auditory canal 16.

[0063] Although the dashed frame, which represents the hearing aid 2, and the auditory canal 16 overlap in the illustration of FIG. 2, the auditory canal 16 is clearly not part of the hearing aid 2. The overlap in FIG. 2 is solely a result of the simplified illustration.

[0064] The hearing aid 2 shown herein is configured for closed care and has the earpiece 4 for this purpose, for closing off the auditory canal 16 during the intended use of the hearing aid 2. The earpiece 4 is, for example, a so-called dome or an otoplastic. In one possible embodiment (not explicitly shown herein), the earpiece 4 also has a so-called vent.

[0065] In the exemplary embodiment shown, the modified, i.e., amplified signal S, the feedback signal fb, and the feedforward signal ff are combined with one another to form an output signal A, which is then output through the receiver 6. In the present case, the modified signal S, the feedback signal fb, and the feedforward signal ff are added to one another in a summing unit 30. The output signal A then contains, on one hand, the amplified signal S output by the signal processing unit 24 and also the correction signals fb, ff for suppressing interference noises. In addition, the output signal A is also amplified by using an auxiliary amplifier 32 of the hearing aid 2, before the output signal A is output through the receiver 6. The modified signal S, the feedback signal fb, and the feedforward signal ff are accordingly jointly more or less post-amplified. The summing unit 30 and the auxiliary amplifier 32 are not significant as such for the underlying concept of the control of the signal processing unit 24 depending on the feedback signal fb and in principle are independent thereof.

[0066] The following is a summary list of reference numerals and the corresponding structure used in the above description of the invention: [0067] 2 hearing aid [0068] 4 earpiece [0069] 6 receiver [0070] 8 internal microphone [0071] 10 external microphone [0072] 12 housing [0073] 14 control unit [0074] 16 auditory canal [0075] 18 ANC unit [0076] 20 feedforward unit [0077] 22 feedback unit [0078] 24 signal processing unit [0079] 26 amplification [0080] 28 signal path [0081] 30 summing unit [0082] 32 auxiliary amplifier [0083] A output signal [0084] Ext external signal [0085] E1 first input signal (from external microphone) [0086] E2 second input signal (from internal microphone) [0087] fb feedback signal, correction signal [0088] ff feedforward signal, correction signal [0089] N noise [0090] P1 external path (acoustic) [0091] P2 internal path (acoustic) [0092] P3 third path (acoustic-electric) [0093] S signal (modified, amplified)