METHOD OF AUDIO REPRODUCTION IN A HEARING DEVICE AND HEARING DEVICE

Abstract

In a method of audio reproduction in a hearing device, a first external signal is provided, a geometric data set is predetermined for a head shape of a user of the hearing device, and a first position is predetermined for a first virtual speaker. A propagation of the first external signal from the first virtual speaker to a first local unit of the hearing device is simulated based on the geometric data set for the head shape of the user and on the first position and a first virtual spatial signal is generated in the process. A first reproduction signal is generated from the first virtual spatial signal, and a first output transducer reproduces the first reproduction signal in the first local unit of the hearing device.

Claims

1. A method of audio reproduction in a hearing device, which comprises the steps of: providing a first external signal; predetermining a geometric data set for a head shape of a user of the hearing device; predetermining a first position for a first virtual speaker; simulating a propagation of the first external signal from the first virtual speaker to a first local unit of the hearing device based on the geometric data set for the head shape of the user and on the first position, and a first virtual spatial signal is generated in the process; generating a first reproduction signal from the first virtual spatial signal; and reproducing, via a first output transducer, the first reproduction signal in the first local unit of the hearing device.

2. The method according to claim 1, which further comprises: determining a first head-related transfer function for the head shape of the user based on the geometric data set and based on the first position; and simulating a propagation of the first external signal, from the first virtual speaker to the first local unit of the hearing device for generating the first virtual spatial signal, using the first head-related transfer function.

3. The method according to claim 1, which further comprises: generating the geometric data set for the head shape of the user by a mobile telephone by means of a number of image recordings; and transmitting the geometric data set to the hearing device as a preset.

4. The method according to claim 1, which further comprises: providing a second external signal; predetermining a second position for a second virtual speaker, simulating a propagation of the second external signal from the second virtual speaker to the first local unit of the hearing device based on the geometric data set for the head shape of the user and on the second position, and a second virtual spatial signal is generated in the process; and generating the first reproduction signal from the second virtual spatial signal.

5. The method according to claim 4, which further comprises: providing a third external signal; predetermining a third position for a third virtual speaker; simulating a propagation of the third external signal from the third virtual speaker to the first local unit of the hearing device based on the geometric data set for the head shape of the user and on the third position, and a third virtual spatial signal is generated in the process; and generating the first reproduction signal from the third virtual spatial signal.

6. The method according to claim 1, which further comprises: simulating a propagation of the first external signal from the first virtual speaker to a second local unit of the hearing device based on the geometric data set for the head shape of the user and on the first position, and an additional virtual spatial signal is generated in the process; generating a second reproduction signal based on the additional virtual spatial signal; and reproducing, via a second output transducer, the second reproduction signal in the second local unit of the hearing device.

7. The method according to claim 1, which further comprises detecting a head movement of the user of the hearing device in order to preset the first position.

8. The method according to claim 1, which further comprises providing a first channel of a multi-channel surround signal as the first external signal.

9. The method according to claim 8, which further comprises providing the first channel of the multi-channel surround signal by direct transmission to the hearing device.

10. The method according to claim 8, which further comprises: transmitting a stereo signal or a mono signal to the hearing device; and providing the first channel of the multi-channel surround signal from the stereo signal or the mono signal, respectively, by preprocessing in the hearing device.

11. A hearing device, comprising: at least one local unit for audio reproduction, said at least one local unit programmed to: provide a first external signal; predetermine a geometric data set for a head shape of a user of the hearing device; predetermine a first position for a first virtual speaker; simulate a propagation of the first external signal from the first virtual speaker to said local unit of the hearing device based on the geometric data set for the head shape of the user and on the first position, and a first virtual spatial signal is generated in the process; generate a first reproduction signal from the first virtual spatial signal; and reproduce, via a first output transducer, the first reproduction signal in the first local unit of the hearing device.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0037] FIG. 1 is a top view of a hearing device with two local units, which its user uses in a surround-sound system;

[0038] FIG. 2 is a block diagram of a method for generating two reproduction signals for the hearing device 4 according to FIG. 1; and

[0039] FIG. 3 is a schematic cross-section through a geometric data set for a head shape of the user of the hearing device according to FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

[0040] Components and magnitudes that correspond to each other are respectively assigned the same reference signs in all drawings.

[0041] Referring now to the figures of the drawings in detail and first, particularly to FIG. 1 thereof, there is shown a schematic top view of a first local unit 1 and second local unit 2 of a hearing device 4. A user 6 of the hearing device 4 must wear the first local unit 1 and second local unit 2 on the left and right ear respectively. The user 6 who wears the hearing device 4 is now surrounded by a surround-sound system 8 containing a front speaker 10, a front left speaker 12, a front right speaker 14, rear left speaker 16 and rear right speaker 18. For better spatial sound, the individual speakers 10 to 18 reproduce different input signals provided by a central unit 19 arranged directly on the front speaker 10. Thus, the front speaker 10 receives a front output signal 20 from the central unit 19, the front left speaker 12 receives a front left output signal 22 from the central unit 19, the front right speaker 14 receives a front right output signal 24, the rear left speaker 16 receives a rear left output signal 26, and the rear right speaker 18 receives a rear right output signal 28.

[0042] In this case, the output signals 20 to 28 are transmitted respectively as external signals to the first local unit 1 and to the second local unit 2 of the hearing device 4, via a corresponding streaming protocol. The central unit 19 transmits the data, but if the speakers 10 to 18 are set up appropriately, the data may also be transmitted via the speakers 10 to 18 themselves, each respectively transmitting their own output signal 20 to 28 to the first local unit 1 and second local unit 2.

[0043] The frontal output signal 20 thus enters the first local unit 1 as a first external signal, the front left output signal 22 enters as a second external output signal, the front right output signal 24 enters as a third external signal, and so on. In the second local unit, these output signals 20 to 28 likewise enter as a first or second or third external signal.

[0044] The external signals 20 to 28 are now each respectively processed in the two local units 1, 2 in such a way that a realistic spatial hearing sensation is created for the user 6, as would be the case with hearing real sounds in the surround-sound system 8.

[0045] This is illustrated schematically for the first local unit 1, by way of example. The hearing device 4 is given information about the positions of the speakers 10 to 18. This may be done by directly transmitting position information from the respective speaker 10 to 18 to the respective local unit 1, 2, or by a corresponding user input. The first local unit 1 now contains a first position 30, a second position 32, a third position 34, a fourth position 36 and a fifth position 38 of the front speaker 10, the front left speaker 12, the front right speaker 14, the rear left speaker 16 and the rear right speaker 18. For each of the positions 30 to 38, the first local unit 1 also provides a respective head-related transfer function for propagating a sound signal from the corresponding speaker 10 to 18 to the first local unit 1. The corresponding head-related transfer function is now used to calculate how a sound signal that a speaker positioned at the first position 30 would generate via the first external signal 20 (which corresponds to the frontal output signal 20), is propagated to the first local unit 1, and is thereby in particular shadowed by the head of the user 6. A virtual spatial signal, which has not yet been described, is thus generated and is used to generate a reproduction signal for the first local unit 1. This reproduction signal of the first local unit 1 also includes the virtual spatial signals that correspond to the other output signals 22 to 28 or the remaining speakers 12 to 18.

[0046] FIG. 2 shows a schematic block diagram of a method for generating a first reproduction signal 40 and second reproduction signal 42 for the hearing device 4 according to FIG. 1. The output signals 20 to 28, which are transmitted as external signals to the first local unit 1 and the second local unit 2, are first respectively filtered with an HRTF 44. The HRTF 44a corresponds to the propagation to the first local unit 1 of a sound signal that a virtual speaker that corresponds to the frontal speaker 10 generated at the first position 30. A comparable situation applies to the other HRTFs 44b to j with regard to the propagation of a sound signal from the second to fifth position 32 to 38 to the first local unit 1 or from the first to fifth position 30 to 38 to the second local unit 2.

[0047] The first external signal corresponding to the frontal output signal 20 is now filtered with the HRTF 44a, generating a first virtual spatial signal 46. Accordingly, the second external signal corresponding to the front left output signal 22 is filtered with the HRTF 44b, generating a second virtual spatial signal 48. Comparably, a third virtual spatial signal 50 is generated from the third external signal, corresponding to the front right output signal 24, and so on. The five virtual spatial signals 46 to 54 are now combined, optionally with a corresponding weighting, to form the first reproduction signal 40. A first output transducer 56 reproduces the first reproduction signal 40 for the user 6 in the first local unit 1 of the hearing device 4.

[0048] Similarly, a second output transducer 58 generates and reproduces the second reproduction signal to the user 6 in the second local unit 2 of the hearing device 4. When generating the second reproduction signal 42, the first external signal corresponding to the frontal output signal 20 in particular is filtered with the HRTF 44f, which corresponds to a sound signal propagating to the second local unit 2 from a virtual speaker positioned at the first position 30. In particular, an additional virtual spatial signal 60 is generated that is used together with the other virtual spatial signals 62 to 68 to form the second reproduction signal 42.

[0049] FIG. 3 schematically shows a cross-section through a geometric data set 70 for a head shape of the user 6 of the hearing device 4 according to FIG. 1. The sectional plane cuts transversely at the height of the ears 72, 73 and nose 74 of the user 6. Plainly, due to symmetry, a sound signal generated by a speaker arranged at the first position 30 may propagate almost in the same way to the left ear 72 as to the right ear 73. For this reason, in FIG. 2 the virtual spatial signals 46, 60 that the corresponding HRTF generates do not differ significantly with respect to the first position 30. This is no longer the case, however, for a sound signal that a speaker arranged at the second position 32 generates, due to the shadowing by the nose 74, which already occurs during propagation to the right ear 73. Accordingly, the corresponding virtual spatial signals that enter into the first or second reproduction signal 40 or 42 are different. A sound signal that a speaker arranged at the fourth position 36 generates is also shadowed by the auricle during propagation to the left ear 72. The shadowing effects of the ears 72, 73 and the nose depend to a considerable extent on the anatomical properties of the user 6. This is all the more the case if the head movements of the user 6 relative to the physical speakers 10 to 18 of the surround-sound system 8 are also recorded in presetting the position of the virtual speakers for which the virtual spatial signals according to FIG. 2 are to be generated.

[0050] Although the invention has been illustrated and described in greater detail with reference to the preferred exemplary embodiment, this exemplary embodiment does not limit the invention. A person of ordinary skill in the art will be able to derive other variations from this exemplary embodiment, without departing from the invention's protected scope.

[0051] The following is a summary list of reference numerals and the corresponding structure used in the above description of the invention: [0052] 1 First local unit [0053] 2 Second local unit [0054] 4 Hearing device [0055] 6 User [0056] 8 Surround-sound system [0057] Front speaker [0058] 12 Front left speaker [0059] 14 Front right speaker [0060] 16 Rear left speaker [0061] 18 Rear right speaker [0062] 19 Central unit [0063] 20 Front output signal, first external signal [0064] 22 Front left output signal, second external signal [0065] 24 Front right output signal, third external signal [0066] 26 Rear left output signal [0067] 28 Rear right output signal [0068] 30 First position [0069] 32 Second position [0070] 34 Third position [0071] 36 Fourth position [0072] 38 Fifth position [0073] 40 First reproduction signal [0074] 42 Second reproduction signal [0075] 44a-j HRTF (head-related transfer function) [0076] 46 First virtual spatial signal [0077] 48 Second virtual spatial signal [0078] 50 Third virtual spatial signal [0079] 52 Fourth virtual spatial signal [0080] 54 Fifth virtual spatial signal [0081] 56 First output transducer [0082] 58 Second output transducer [0083] 60 Additional virtual spatial signal [0084] 62-68 Other virtual spatial signals [0085] 70 Geometric data set [0086] 72 Ear (left) [0087] 73 Ear (right) [0088] 74 Nose