Hearing device, particularly hearing aid

Abstract

A hearing device, particularly a hearing aid, has a housing, a signal processing unit arranged in the housing, a first sound generator disposed in the housing, and a second sound generator. The first sound generator and the second sound generator are configured to convert an output signal from the signal processing unit into sound. The second sound generator is a thermo-acoustic transducer.

Claims

1. A hearing device, comprising: a housing; a signal processing unit disposed in said housing and having an output for carrying an output signal; an electro-acoustic transducer forming a first sound generator arranged in said housing; a thermo-acoustic transducer forming a second sound generator, said thermo-acoustic transducer having a plurality of signal ports and at least one film connected to at least one said signal port and formed from carbon nanotubes, and wherein an application of a signal voltage to said signal port brings about time-variant heating in said at least one film and produces a sound by way of a thermo-acoustic effect; said first and second sound generators being configured to convert an output signal from said signal processing unit into sound; a frequency filter having a signal input connected to receive the output signal from said signal processing unit, a low-frequency output connected to said first sound generator, and a high-frequency output connected to said second sound generator.

2. The hearing device according to claim 1, wherein said second sound generator is arranged in said housing.

3. The hearing device according to claim 1, wherein said first sound generator is configured to have a higher maximum reproduction level for frequencies in a frequency range up to 4 kHz than for frequencies above 4 kHz.

4. The hearing device according to claim 1, wherein said housing has an acoustic space formed therein with a sound output, said first sound generator is configured to generate sound in said acoustic space, and said second sound generator is arranged in said acoustic space.

5. The hearing device according to claim 4, wherein said second sound generator is arranged in a sound path between said first sound generator and said sound output.

6. The hearing device according to claim 4, wherein said second sound generator is arranged laterally to a of a sound path between said first sound generator and said sound output.

7. The hearing device according to claim 1, configured as a hearing aid.

8. A hearing device, comprising: a housing; a signal processing unit disposed in said housing and having an output for carrying an output signal; a first sound generator arranged in said housing; a sound conductor reversibly connectable to said housing and having at least one signal port; a thermo-acoustic transducer forming a second sound generator arranged in said sound conductor, said thermo-acoustic transducer having a plurality of signal ports and at least one film connected to at least one said signal port and formed from carbon nanotubes, and wherein an application of a signal voltage to said signal port brings about time-variant heating in said at least one film and produces a sound by way of a thermo-acoustic effect; said first and second sound generators being configured to convert an output signal from said signal processing unit into sound; a frequency filter having a signal input connected to receive the output signal from said signal processing unit, a low-frequency output connected to said first sound generator, and a high-frequency output; and wherein, when said sound conductor is connected to said housing, said at least one signal port of said sound conductor produces a signal connection from said high-frequency output of said frequency filter to said second sound generator.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

(1) FIG. 1 shows a schematic sectional illustration of a hearing device having a conventional transducer and a thermo-acoustic transducer; and

(2) FIG. 2 shows a similar sectional illustration of the hearing device shown in FIG. 1 having an alternative arrangement of the thermo-acoustic transducer.

DETAILED DESCRIPTION OF THE INVENTION

(3) Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is shown, in a schematic sectional illustration, a hearing device 1 that, in this case, is in the form of a hearing aid 2. The hearing device 1 comprises a housing 4 in which a modular unit 6 has been inserted. The modular unit 6 has an interior housing 8 that surrounds, or encases, an acoustic space 10. The interior housing 8 of the modular unit 6 contains a first sound generator 12 on a damping suspension 14. In this case, the first sound generator 12 is in the form of a conventional, electro-acoustic transducer. In addition, the interior housing 8 of the modular unit 6 contains a second sound generator 16 that is in the form of a thermo-acoustic transducer 18. The second sound generator 16 has two signal terminals, or ports 20 and a film 22 comprising carbon nanotubes. The film 22 may also be referred to as a nanotube sheet 22.

(4) To generate a sound signal, the interior housing 8 first of all contains a signal filter, or signal splitter 24 having a signal input 26 for receiving an output signal 28 from a signal processing unit 30. From a low-frequency output 32 of the signal filter 24, a low-frequency connection 34 is routed to the first sound generator 12. In addition, the signal filter 24 has a high-frequency output 36, from which high-frequency connections 38 are routed to each of the signal ports 20 of the thermo-acoustic transducer 18. The output signal 28 that is output by the signal processing unit 30 is broken down into a low-frequency component and a high-frequency component in the signal filter 24.

(5) The low-frequency component of the output signal 28 is output at the low-frequency output 32, via the low-frequency connection 34, to the first sound generator and converted by the latter into sound having predominantly low frequencies. In this case, the sound generated by the first sound generator 12 propagates primarily in the acoustic space 10 to a sound output 40, which forms a sound path 44. In this case, the sound output 40 has a rubber connecting piece 42 onto which a sound conductor, e.g., a sound tube, which is not shown in more detail, can be fitted for conveying the sound generated in the acoustic space 10 to a further earmold and ultimately to the eardrum of the user of the hearing device.

(6) The high-frequency signal component of the output signal 28 is output at the high-frequency output 36, via the respective high-frequency connections 38, to the thermo-acoustic transducer 18 and converted by the latter into sound having predominantly high frequencies. In this case, the arrangement of the thermo-acoustic transducer 18 in the sound path 44 of the first sound generator 12 has no significant effects on the sound from the first sound generator 12 and the propagation thereof on account of the microstructure of the carbon nanotube film 22.

(7) The first sound generator 12 is designed as an electro-acoustic transducer for powerful sound generation up to frequencies of 3 kHz, and above these frequencies, the reproduction spectrum decreases continuously up to complete cutoff at approximately 6-7 kHz. The thermo-acoustic transducer 18 is designed for particularly powerful sound generation in the range from approximately 1 kHz to 15 kHz. The acoustic design of the reproduction power of the thermo-acoustic transducer 18 has a certain degree of freedom, but the lower limitthat is to say the frequency from which the thermo-acoustic transducer is able to produce a significant sound pressurefor the frequency range needs to be chosen such that a significant overlap with the reproduction spectrum of the first sound generator 12 is assured, and the upper limitfrom which the sound pressure that can be produced decreasesis dependent primarily on the frequencies that are still desired and/or required for the respective application.

(8) Since the output signal 28 is split by the signal filter 24 into a low-frequency component and a high-frequency component that are each converted into sound by different sound generators, the gains for corresponding frequency bands can be optimized in the signal processing unit 30 to the effect that the most dynamic reproduction possible is obtained for the lowest possible feedback into a microphone, which is not shown in more detail in the drawing, of the hearing device 1. The damping suspension 14 of the first sound generator 12 can firstly partially absorb mechanical vibrations in the first sound generator. The first sound generator can furthermore be optimized for operation with the least vibration possible in the low-frequency range.

(9) Such optimization of operation is in most cases possible only for particular, restricted frequency bands owing to the mechanical complexity of sound generators that are typically used in a hearing device. The use of a first sound generator 12 and of a second sound generator 16 now firstly allows the first sound generator to be optimized in terms of its reproduction and vibration properties in the low-frequency range, and allows the second sound generator to be optimized for maximum gain in particular higher frequency bandse.g. in the range from 2 kHz to 4 kHz that is relevant for speech intelligibility.

(10) The arrangement of a second sound generator 16 in a hearing device 1 is usually unimplementable for reasons of space. The use of a thermo-acoustic transducer 18 means that said thermo-acoustic transducer is possible, however, in combination with a conventional, electro acoustic transducer, as exists in the first sound generator 12. Owing to the microstructure of the film 22 comprising carbon nanotubes, which microstructure equates to a fine tissue through which the sound from the first sound generator 12 can propagate, there are also no restrictions for the arrangement of the thermo-acoustic transducer 18 in relation to the sound path 44.

(11) FIG. 2 shows a sectional illustration of an alternative arrangement of the thermo-acoustic transducer 18 in a hearing device 1 that, apart from the positioning of the thermo-acoustic transducer 18, is already illustrated in FIG. 1. In this case, the thermo-acoustic transducer 18 is arranged not in the sound path 44 for the sound that propagates from the first sound generator 12 to the sound output 40 of the acoustic space 10, but rather to the side of and longitudinally in relation to the sound path 44. In this case, the specific selection of the arrangement can be made dependent on the required dimensioning of the thermo-acoustic transducer 18, particularly of the carbon nanotube film 22, which dimensioning is in turn linked to the desired optimum frequency response of the second sound generator 16.

(12) To complete the illustration, FIG. 2 shows a sound conductor 46, one end of which has a male connector 48. In this case, the male connector 48 is plugged into the rubber connecting piece 42, which produces a vibration-damped mechanical connection between the hearing device 1 and the sound conductor 46. In addition, the sound conductor 46 has a signal port 50 and a third sound generator 52, which, like the second sound generator 16, is likewise in the form of a thermo-acoustic transducer 54. In this case, the signal port 50 is connected to the thermo-acoustic transducer 54, so that a corresponding contact pin on the housing 4 of the hearing device or on the interior housing 8 can be used to produce a signal connection 56 between the thermo-acoustic transducer 54 and the signal processing unit 30.

(13) As an alternative to the illustration shown in FIG. 2, it is also conceivable for the second sound generator that is in the form of a thermo-acoustic transducer to be arranged in the sound conductor, and an appropriate signal connection connects to the signal processing unit directly via contact pins or indirectlyvia a high-frequency output of a signal filter. In this case, the first sound generator in the housing of the hearing device generates primarily low-frequency sound that propagates directly into the sound conductor. There, the high-frequency sound is added by the thermo-acoustic transducer for a signal having the greatest bandwidth possible converter.

(14) Although the invention has been illustrated and described in more detail by the preferred exemplary embodiment, the invention is not restricted by this exemplary embodiment. Other variations can be derived therefrom by a person skilled in the art without departing from the scope of protection of the invention.

(15) The following is a summary list of reference numerals and the corresponding structure used in the above description of the invention: 1 Hearing device 2 Hearing aid 4 Housing 6 Modular unit 8 Interior housing 10 Acoustic space 12 First sound generator 14 Damping suspension 16 Second sound generator 18 Thermo-acoustic transducer 20 Signal port/terminal 22 Film comprising carbon nanotubes 24 Signal filter, signal splitter 26 Signal input 28 Output signal 30 Signal processing unit 32 Low-frequency output 34 Low-frequency connection 36 High-frequency output 38 High-frequency connection 40 Sound output 42 Rubber connecting piece 44 Sound path 46 Sound conductor 48 Male connector 50 Signal port 52 Third sound generator 54 Thermo-acoustic transducer 56 Signal connection