EP0723381B2 - Device for hearing assistance - Google Patents

Abstract

The device has two microphones (2,3) coupled to a control unit (1). The microphones (2,3) supply the control unit (1) with input signals. The control element (1) transmits at least one output signal to at least one transmission element (8). The control unit (1) is spatially separated from the microphones (2,3). Each microphone (2,3) is held in an ear housing (4,5) which can be arranged near the ear (22). Each housing (4,5) has a transmitter (6) which communicates with a receiver (7) near the control unit (1). A transmitter element (8) is arranged near at least one of the housings (4,5) and has a receiver (9). This communicates with a transmitter (10) near the control unit (1). A comparator (12) analyses the microphone signals and modifies the output power of the control unit (1) to adapt to a spatial sound reproduction.

Description

The invention relates to a device for hearing support, which has two microphones with one Control unit are coupled and the control unit with Feed input signals and at which the control unit at least one output signal to at least one Transmission element transmitted and at which the control unit spatially separated from the microphones is, as well as with the microphones in the area of a human ear can be arranged in ear housings are recorded and in which the ear housings each are provided with a transmitter with a receiver communicates in the area of the control unit, and in the area of at least one of the ear housings one of the transmission elements is arranged, the is provided with a receiver with a transmitter communicates in the area of the control unit as well with an analyzer in the area of the control unit Evaluation of the signals of the microphones is arranged.

A device is already known from FR-A-2 651 634 known for hearing support, in which a microphone with a control unit is coupled and in which the control unit spatially separated from the microphone is. The microphone is in the area of an ear casing arranged that is recordable by a human ear is. Communication takes place via a Receiver and a transmitter and in the area of the control unit is an analyzer for evaluating the signals arranged the microphone.

DE-A-2 406 218 discloses a device for Hearing support is described with two microphones be used. However, both microphones are arranged in a common ear housing. At least one of the microphones has a directional characteristic on. The signals from the two microphones are in the Processed area of a control unit.

Another device is known from WO-A-89 04 583 known for hearing support. According to this A microphone is printed in the area of an ear housing arranged, which is arranged with a spatially separate Control unit Via one transmitter and one Receiver communicates.

A comparable device is from DE-OS 35 12 999 known. Through a different orientation of the microphones and a subsequent subtraction the output signals of the microphones from each other it should enable one in all listening directions to eliminate effective ambient noise. The Transmission element is designed here as a loudspeaker.

From DE-OS 35 08 830 it is known locally separated from a speaker in an ear case is arranged, which in turn by one human ear recordable or behind can be arranged in a human ear, in the area of a separate control unit, a microphone, an amplifier and arrange a power source. Through this device is it possible in the human realm Component ear to be arranged relatively easy to construct. A wireless transmission of signals to one Hearing aid is described in DE-OS 30 32 311. Here is thought of signals to be transmitted wirelessly, for example from a telecommunications system or provided a radio become. Another construction in which a spatial Separation of loudspeaker and control unit provided is described in DE-OS 28 44 979. The microphone is also in the area of the control unit arranged.

DE 31 00 135 C2 is already a device known for hearing support, the two microphones has, which are coupled to a control unit. The Microphones feed the control unit with input signals. The control unit transmits at least one output signal to at least one transmission element. The control unit is spatially separated from the Microphones arranged and each of the microphones is from accommodated in a housing. One of the transmission elements is arranged in the area of an ear housing. There is a comparator in the area of the control unit provided for evaluating the signals of the microphones, which is the output power of the control unit Modification adapted to sound reproduction.

DE 30 27 384 describes a method for forming described by sound signals, in which the unnatural Directional sensations through the forming regarding the directional impressions in the natural Hearing sensations better approximated hearing sensations can be converted.

DE 41 01 933 A 1 describes a control unit for directional microphone signals for the generation of virtual Directional characteristics with adjustable main reception direction. The output signal is multiplied by Evaluation of the input signals with control parameters educated.

DE 35 30 205 Al already has a microphone system known with variable directional characteristic, the one Row of microphones that are equidistant are arranged to each other. The directional pattern is due to a special row-like arrangement of the microphones and by using a weighting network realized with weighting factors.

DE 29 28 845 A1 describes an audiovocal integration device described, which has a microphone, that through a special device with a vibrator is coupled, the vibrations on the skin of a user can muster. About a corresponding one Control takes place a coordination of the acoustic as well as the sensitive signal transmission.

According to this state of the art are either Devices for hearing support are known at which all components in the field of human Arranged ear, or in which at one spatial separation of components in the area only one loudspeaker is provided for the ear and the other components, especially the amplifier and the microphones, in a spatially separated area control unit arranged by the loudspeaker are provided. It is not with these devices satisfactorily possible for one user a replica of the natural sense of hearing to enable spatial hearing and at the same time a Suppression of noise.

The object of the present invention is a To construct a device of the type mentioned in the introduction, that both ensures good acoustic quality is also perceived as pleasant Ease of use is realized.

According to the invention, this object is achieved by that the analyzer the output power of the control unit for adaptation to spatial sound reproduction modified that output signals of the microphones be evaluated comparably by the analyzer and that in the area of at least one of the transmission elements an ear amplifier is arranged, and that the control unit for manual inputs has an operating unit.

With the help of the arrangement of the microphones within the Ear housing becomes an orientation of sound reception in different directions according to usual Listening habits performed. In particular this makes it possible to reduce noise through targeted Compensate directional hearing. It is possible, a central evaluation of the signals of the individual Perform microphones.

With the help of the comparator, for example, a Useful noise- interference noise selection process carried out be there in the presence of hearing loss enables the person concerned, by moving the Head or equivalent setting in the area the control unit is regarded as dominant Perceive sound source predominantly. It is there regardless of whether the acoustic signals are Speech, music or typical noise. In particular, it is possible with a monoaurally supplied To reproduce a hearing sensation for the hearing impaired, that is largely a normal spatial hearing corresponds. This results from the fact that the hearing impaired by moving his head and through the appropriate signal evaluation Can locate sound source.

Due to the arrangement of the microphones in ear housings, that can be inserted into the ear and through the relocation of all other elements to the area of the spatially separated control unit realizes a hearing aid that is barely perceptible to the eye with high sound quality no visual restrictions the appearance of the device equipped people.

This makes it particularly easy to use provided that for data transmission from the Transmitters to the receivers a transmission path is provided. This can be wireless.

To ensure high transmission security it is also possible that the transmitter with the Receivers are connected via a line.

To support directional hearing, it is proposed that the comparator with an envelope correlator is provided.

Another improvement in directional hearing can also be done in that the comparator with a Time correlator is provided.

An ergonomically particularly useful arrangement the control unit takes place in that the control unit in the area of a wearable on a wrist Bracelet is arranged.

Another variation on directional listening is thereby provided that in the area of the control unit a directional microphone is arranged.

To power the ear amplifier as well further components is provided that in the area at least one of the ear housings arranged an ear battery is.

To avoid inappropriate volume proposed that in the area of the control unit for at least one transmission channel a level limiter is provided.

A sufficient intensity of that from the control unit emitted signals can take place that in the area of the control unit a main amplifier is provided.

Adequate sound energy in the area of Ear casing is provided in that in the area at least one of the transmission elements is an ear amplifier is arranged.

Fig. 1

ein Blockschaltbild mit einer Anordnung mit zwei Mikrofonen sowie örtlich getrennt angeordneter Steuereinheit, bei derdie übertragung leitungsgebunden erfolgt,

Fig. 2

eine vergrößerte Darstellung der Steuereinheit gemäß Fig. 1,

Fig. 3

eine Prinzipdarstellung zur Veranschaulichung eines räumlichen Hörvorganges,

Fig. 4

eine im Bereich eines Armbandes angeordnete Steuereinheit,

Fig. 5

eine Prinzipdarstellung zur Veranschaulichung einer Hüllkurvenkorrelation und

Fig. 6

eine Prinzipdarstellung zur Veranschaulichung einer Zeitkorrelation.

Exemplary embodiments of the invention are shown schematically in the drawing. Show it:

Fig. 1

2 shows a block diagram with an arrangement with two microphones and a control unit which is arranged at a separate location, in which the transmission is conducted in a line-bound manner,

Fig. 2

2 shows an enlarged illustration of the control unit according to FIG. 1,

Fig. 3

a schematic diagram to illustrate a spatial hearing process,

Fig. 4

a control unit arranged in the area of a bracelet,

Fig. 5

a schematic diagram to illustrate an envelope correlation and

Fig. 6

a schematic diagram to illustrate a time correlation.

The device for hearing support is according to the embodiment in Fig. 1 from a control unit (1), two microphones (2,3) and ear housings (4,5), in which the microphones (2,3) are installed and the have a shape that allows the earhousing (4,5) in the area of an auricle or one Arrange ear canal of a human ear. Each of the microphones (2, 3) is in the area of the ear housing (4,5) assigned to a transmitter (6), each with one Receiver (7) in the area of the control unit (1) communicates. According to the embodiment in FIG. 1 additionally in the area of each of the ear housings (4,5) a transmission element (8) arranged with each one also in the area of the ear housing (4,5) arranged receiver (9) is connected. The Receivers (9) receive their signals from transmitters (10), which are arranged in the area of the control unit (1). For the immediate supply of the transmission elements (8) are ear amplifiers in the area of the ear housing (4,5) (11) arranged.

The control unit (1) is equipped with a comparator (12) provided an evaluation of the signals from the microphones (2,3) relative to each other enables a spatial Listen to replicate and suppress noise. When the transmission elements are formed (8) as a speaker is provided, for limitation the radiated in the area of the speakers Sound energy in the area of the control unit (1) level limiter (13) to be arranged. For energy supply the control unit (1) has a main battery (14). The ear casing (4,5) can be used for energy supply the components with ear batteries (15). The transmission elements (8) can also be used as electrodes be trained that electrically on the auditory nerves act.

The detailed structure of the control unit (1) results from Fig. 2. The overall function is of a Controller (16) monitors. As additional assemblies are in addition to the level limiters already mentioned (13), the comparator (12), the main battery (14) and the receivers (7) and the transmitters (10), a service unit (17), a display (18) a directional microphone (19) and a frequency filter (20) are provided. A level adjustment takes place via a main amplifier (34). When selecting a sound pattern, the controller (16) predefined tables are accessed through which a setting of the frequency filter (20) and the level limiter (13) is possible.

A schematic diagram to illustrate one spatial hearing is shown in Fig. 3. An individual (21) has his ears (22) here in one direction of hearing (23) aligned. With side sound radiation (24) a sound impulse strikes the Ears (22). Sound pressure profiles (25) thus have a temporally offset in the area of the ears (22) Course and different levels. At a Frontal sound radiation (26) are the sound pressure profiles (25) in the area of the ears (22), however, essentially congruent in time.

According to the embodiment in Fig. 4 is particular thought of the control unit (1) in the area of a Arrange bracelet (27), which in turn in Fixed area of a human wrist (28) can be. In confined spaces it is also possible to use some of the components of the Control unit (1) in the area of links of the bracelet (27) to be installed.

To illustrate how the comparator works (12) are a circuit variant for an envelope correlation and in Fig. 6 a circuit variant shown for a time correlation. At 5 are the microphones (2,3) each connected to a frequency separator (29). The frequency separator (29) has individual frequency ranges assigned separate outputs (30) on. For example, it is possible to use a separator outlet the frequency range from 0 - 0.5 kHz, the next Separator output (30) the frequency range of 0.5 - 1 kHz and the other frequency ranges additional Assign separator outputs (30). With help Envelope correlators (31) are used to analyze the Determination of sound pressure level differences between the microphones (2,3). Such a sound pressure level difference occurs in one of the frequency ranges, so only the weaker signal component becomes the overall signal added. This takes advantage of the fact that laterally incident Sound waves facing away from the sound source Ear or the assigned microphone (2,3) with a level difference as well as a time difference. In principle it is appropriate to both the level difference according 5 as well as the time difference according to to take advantage of the variant in FIG. 6.

When performing the time correlation according to Fig. 6, a time correlator (32) is used and a Coupling takes place according to a bypass Attenuators (33).

Both the envelope correlation and the time correlation can be technically analog or digital will be realized. In particular, it is thought an improvement by combining the two methods to enable sound detection. For Ensure adequate detection of Loudness differences between the left and right Ear it is appropriate to use the correlation method only to be activated when there is frontal radiation (26) is present.

With the help of those worn in the area of the wrist (28) Control unit (1) it is possible to make a change make the settings made, without changing the position of the microphones (2, 3). This means that not within the Ears (22) arranged ear housing (4,5) accessed must become. The directional microphone (19) can by a corresponding movement of a forearm of the individual (21) can be positioned.

In addition, external audio inputs and audio outputs will be realized. With the help of these additional devices it is possible to get warning signals or phone signals to generate, send, receive and to Listen.

By the control unit (17) in the area of Control unit (1) it is possible to have a predefinable gain of signals from one of the microphones (2, 3). This allows the user to avoid his Head towards the desired sound source rotate. It is also possible with the help of the control unit (17) to adjust the volume, make a microphone selection or Specify sound group program selection.

With a wired coupling between the earhouses (4,5) and the control unit (1) the transmitters (6, 10), for example, as output amplifiers and the receivers (7, 9) as input amplifiers realized. With a wireless connection are standardized and therefore inexpensive radio elements can be used. A radio connection can be used to suppress interference for example certain transmission frequencies be reserved, so it is also possible alternative To provide transmission channels or alternative To maintain modulation frequencies. A wireless one Transmission can also take place via IR or HF signals.

The device can have different applications be fed. With the one already described Using it as a hearing aid it is possible to record a sound Via the microphones (2,3) in the area of the ear housing (4,5). Alternatively, it is possible to use one Sound recording via a in the area of the bracelet (27) arranged microphone to perform. Further Sound recordings can be made externally, for example via a telephone, a radio, a surveillance microphone, Consumer electronics devices, personal computers or alarm detector.

When used as a hearing aid, the signals are processed in the area of the central unit, which is the comparator (12), the level limiter (13), the frequency filter (20) and a corresponding amplifier (34) can have. The comparison of the time and level difference between the spectral components of the left and Right microphone signal optionally leads to noise suppression. The signal components with time and Level difference not increased. A user of the device is thus able to primarily perceive the sound source, to which he has the front of his head turns.

The microphones (2, 3) are inside the Ohmuscheln arranged, so are those coming from behind Signals attenuated by the auricle. Recognizes the comparator (12) that almost exclusively signals with There is no time and level difference sound suppression made. For example, if a conversation partner is on the left or right side of the user sits and talks and a conversation partner sitting opposite is silent. When recording sound over that in the area of the bracelet (27) arranged microphone or for sound recordings External audio units do not suppress side noise carried out.

With a wired connection between the central unit and the components within the Ear case (4,5) are in the area of the ear case (4,5) no amplifier and no power supply required. If necessary, a preamplifier can be used be useful for sending. When using as a hearing aid, the sound is reproduced via at least one of the loudspeakers in the area of the ear housing (4.5). If the side noise suppression at one Inserted inner ear implant, so the side sound suppressed Signal fed to the processor that the controls implanted electrodes. Through the electrodes there is a charm of the Hömerven.

For applications outside the area of application hearing aids are picked up by a microphone in the area of the central unit. Through signal processing in the area of the central unit can be optional noise suppression can be carried out. The sound is reproduced externally, for example via the same device, a telephone, a radio, a personal computer or an alarm device.

It is also possible in such applications to provide an external sound recording. This can, for example, over a telephone, a radio security microphone, a consumer electronics device, a personal computer or an alarm device respectively. The signal processing in the central unit can optionally with a speech recognition or Speech generation. A Sound reproduction takes place with an external sound recording via at least one speaker in one Ear case (4,5). Sound reproduction is also conceivable via a loudspeaker in the area of Central unit to perform.

The signal transmission between the microphones (2,3) in the area of the ear housing (4,5) and the central unit can be done both analog and digital. It is also possible to use analog signal processing or digitally. According to the respective Boundary conditions is also a mixed analog and digital processing possible. According to each selected processing sequence will be analog-to-digital conversions or digital-to-analog conversions carried out. With a partial analog version is particularly thought of reinforcement operations to be carried out analogously.

For performing digital signal processing are picked up by the microphones (2,3) Signals digitized and into individual frequency bands disassembled. As a result, the individual spectral components are available available for further evaluation. The decomposition can be done, for example, by Fast Fourier Transformations (FFT) or through the use of filter banks respectively. After performing the separation in the frequency bands it is possible to suppress side noise, a frequency response correction, a dynamic compression, a dehumidification or other procedures to improve speech intelligibility perform.

With a frequency response correction will be accordingly an existing hearing impairment for the individual Frequency ranges the required dynamic corrections carried out. It is useful to Ensuring adequate listening comfort not to exceed a maximum value.

Dynamic compression takes into account that a dynamic range for normal hearing within from 0 dB to 130 dB. In the event of hearing loss are noises until a certain one Perceived threshold of volume. This is also frequency dependent. The dynamic range is restricted. E.g. a linear gain of all noises, so should be amplitudes above the discomfort threshold, for example above a limit of 130 dB, be cut off. It is therefore cheaper to Maintain amplitude course and the limited Compress dynamic range.

It is also related to the dehumidification possible to provide an anti-feedback. Is the signal digitized, it can be determined whether hall influences and there can be a minimization of the Hall effect can be performed. Digitization enables an evaluation of the signals. About that it can also be determined whether by the amplifier an additional reinforcement of the already reinforced Signals has been performed. By a time delay of the signal, it is possible to occur To suppress feedback effects.

Improving speech intelligibility can be performed by special algorithms that lead to an increase in sharpness of speech.

All the measures described above for influencing the signal can be used as algorithms for editing be formulated on a digital computer. It is advisable the algorithms each one specific Spectral component to increase or decrease the dynamic value assign. After a corresponding split of the signal into the spectral components and the application one of the algorithms described Recombination to a resulting overall signal. This can be done, for example, by inverse Fast Fourier Transformation or one of the initial filtering appropriate inverse filtering is done.

As an alternative to a complete digital implementation of the algorithms it is also possible to use a partial one analog implementation. Especially for frequency response correction and dynamic compression can be done by applying analog techniques Advantages are achieved. As an alternative to the one described above analog implementation of envelope and time correlator digital algorithms are preferred used. This results in stair curves as the envelope.

Claims (10)

1. A device for hearing assistance, which comprises two microphones (2, 3), which are coupled to a control unit and supply the control unit (1) with input signals and in which the control unit (1) transmits at least one output signal to at least one transmission element and in which the control unit (1) is arranged spatially separate from the microphones (2, 3), and in which the microphones (2, 3) are accommodated in ear housings (4, 5) which can be arranged in the region of a human ear (22) and which are each provided with a transmitter (6), which communicates with a receiver (7) in the region of the control unit (1), and in which one of the transmission elements (8) is arranged in the region of at least one of the ear housings (4, 5), the transmission element (8) being provided with a receiver (9), which communicates with a transmitter (10) in the region of the control unit (1) and in which an analyser (12) for evaluating the signals of the microphones (2, 3) is arranged in the region of the control unit (1), characterised in that the analyser (12) modifies the output power of the control unit (1) for adaptation to three-dimensional sound reproduction, output signals of the microphone (2, 3) are evaluated by being compared by the analyser (12), and an ear amplifier (11) is arranged in the region of at least one of the transmission elements (8) and that the control unit (1) comprises an operating unit (17) for manual input.
2. A device according to claim 1, characterised in that a transmission path is provided for data transmission from the transmitters (6, 10) to the receivers (7, 9).
3. A device according to claim 1, characterised in that the transmitters (6, 10) are connected to the receivers (7, 9) via a line.
4. A device according to one of claims 1 to 3, characterised in that the analyser (12) is provided with an envelope curve correlator (31).
5. A device according to one of claims 1 to 4, characterised in that the analyser (12) is provided with a time correlator (32).
6. A device according to one of claims 1 to 5, characterised in that the control unit (1) is arranged in the region of an arm band (27) which can be worn on a wrist (28).
7. A device according to one of claims 1 to 6 characterised in that a directional microphone (19) is arranged in the region of the control unit (1).
8. A device according to one of claims 1 to 7, characterised in that a level limiter (13) is provided in the region of the control unit (1) for at least one transmission channel.
9. A device according to one of claims 1 to 8, characterised in that a main amplifier (43) is provided in the region of the control unit (1).
10. A device according to one of claims 1 to 9, characterised in that an ear battery (15) is arranged in the region of at least one of the ear housings (4, 5).

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