EP2519033A2 - Method for operating a hearing aid with reduced comb filter perceptio and hearing aid with reduced comb filter perception - Google Patents

Abstract

The method (100) involves detecting (101) an acoustic signal and a linear and/or rotatory acceleration value of a hearing device. A phase modulation is applied (103) to the detected acoustic signal if the acceleration value is greater than a threshold value. A modulated phase is modulated by a noise function. The detected acoustic signal is amplified and outputted (104) via a receiver. The acoustic signal and the acceleration value are again detected if an abort criterion i.e. determined switching state of an operating element of the hearing device, is not fulfilled. An independent claim is also included for a hearing device.

Description

The present invention relates to a method of operating a hearing aid with reduced comb filter perception. Moreover, the present invention relates to a hearing aid with reduced comb filter perception.

A hearing aid is used to supply a hearing-impaired person with acoustic ambient signals that are processed and amplified for compensation or therapy of the respective hearing impairment. It comprises in principle one or more input transducers, a signal processing device with an amplifying device or an amplifier and an output transducer. The input transducer is typically a sound receiver, e.g. a microphone, and / or an electromagnetic receiver, e.g. an induction coil. The output transducer is typically used as an electroacoustic transducer, e.g. a miniature speaker, or as an electromechanical transducer, e.g. a bone conduction listener, realized. He is also referred to as a handset or receiver. The output transducer generates output signals that are routed to the patient's ear and produce a hearing sensation in the patient. The amplifier is usually integrated in the signal processing device. The power supply of the hearing aid is effected by a battery arranged in the hearing aid housing. The essential electronic components of a hearing aid are usually arranged on a printed circuit board as a circuit carrier or connected thereto.

Hearing aids are known in various basic housing configurations. For in-the-ear (in-the-ear) hearing aids, an enclosure containing all the functional components, including the microphone and receiver, is mostly worn in the ear canal. CiC hearing aids (Completely-in-Canal) are similar to the IdO hearing aids, but are fully worn in the ear canal. In BTE hearing aids (behind-the-ear, behind the ear), a housing with components such as battery and signal processing equipment is worn behind the ear and a flexible sound tube, also referred to as a tube, directs the acoustic output signals of a receiver from the housing to the ear canal , RiC-BtE hearing aids (receiver-in-canal behind-the-ear) are similar to BTE hearing aids, but the receiver is worn in the ear canal and instead of a sound tube, which conducts acoustic signals to an earpiece, conducts a flexible cable, also called Earpiece or handset connection means electrical signals to a receiver which is attached to the front of the cable.

Hearing aids generally have an ear piece which, in the case of a BTE hearing aid, is located at the end of the sound tube and, in the case of an RIC BTE hearing aid, near the receiver and is inserted into the ear canal. In other housing configurations, the housing or parts thereof may take over the function of the earpiece.

A distinction is made roughly between closed, so-called "close fitting", ear pieces and open, so-called "open fitting" ear pieces, where "open" and "closed" essentially refers to the sound transmission, which in turn depends on material properties and on the mechanical properties Sealing effect of the earpiece depends.

Open earpieces, which are essentially intended to keep the sound tube or tube with the earpiece centered in the ear canal, are generally more comfortable in terms of wearing comfort because they put less pressure on the ear canal and allow for better venting of the ear canal. Acoustically open ear pieces have the advantage that the possible pressure equalization in the ear canal closure effects, such as an unnatural-sounding own voice or transmitted through structure-borne Kaugeräusche be avoided.

Besides the disadvantage of open earpieces, they are not suitable for large gain factors because of acoustic feedback effects. In case of severe hearing damage, can be used in their use also so-called comb filter effects, or English "comb filter effects" train. The superimposition of a direct sound signal and the delayed by the signal processing means sound signal of the hearing aid leads to gains of certain frequencies and attenuation of other frequencies. In the extreme case, the amplitude doubles at frequencies whose period or multiples thereof are equal to the delay time, or cancel the signals if the delay time is exactly between integer multiples of the period. With different strengths of direct and amplified signal, the change in the resulting signal is between the extremes mentioned. The perceptible auditory impression when comb filter effects occur is a tone discoloration, such as an unnatural, often metallic sound, especially at lower frequencies.

Common methods for reducing the perception of comb filter effects are the reduction of gain from lower frequencies, i. the use of a high-pass filter, or the use of closed ear pieces. A disadvantage of the first method is that the information content of the useful signal is limited by the filtering. A disadvantage of the use of closed ear pieces is, compared to open ear pieces, poorer comfort and possible closure effects.

The object of the present invention is therefore to specify a method for operating a hearing device with reduced comb filter perception. Furthermore, the object of the invention is to provide a hearing aid with reduced comb filter perception.

The invention solves this problem with a method for operating a hearing aid having the features of the first independent patent claim and a hearing aid having the features of the second independent claim.

The basic idea of the invention is a method for operating a hearing device, in which a head movement of a hearing aid wearer is detected and, in the case of a detected head movement, an acoustic signal detected with a microphone is amplified and output in phase modulated form with a receiver.

This technique uses a natural ability of the human brain to block out comb filter effects so that they are not consciously perceptible. In a natural environment, humans are exposed to sound situations in which comb filter effects are also formed. If, for example, music is output in a room via a loudspeaker, the sound is reflected on the walls and reaches the ears of a listener with a time delay to direct sound. The occurring comb filter are measurable, but are not consciously perceived by the listener. It is believed that the human brain is able to integrate and thus eliminate sound impressions of both ears over time and in the frequency domain. In addition, the human constantly performs small, sometimes smallest head movements, which cause on the one hand, that the characteristic, ie the amplitude response, the comb filter constantly varies and, secondly, that the phase of the acoustic signals that hit the right and left ear, constantly varied. By combining the changing auditory impressions of the two ears and the knowledge of the head movement, the human brain is able to wipe out comb filter effects. However, if an acoustic signal which has been subjected to a comb filter is supplied directly to the ear, as is the case, for example, when using a hearing aid, comb filter effects can be heard. The inventive method solves this problem in that the head movement of a hearing aid wearer, for example by evaluation an output signal of an acceleration sensor, which is arranged on or in the hearing aid and thus experiences the same accelerations as the head is monitored. When a head movement is detected, the phase, ie the delay, of the acoustic signal detected and amplified by a microphone is constantly varied, ie a phase modulation of the hearing aid signal takes place. These small variations in the amplified hearing aid signal simulate the natural effect that allows the human brain to block out comb filter effects. In other words, the variations in the phase position of the hearing aid signal that are performed during the detection of head movements lead to a variation of the comb filter characteristic, whereby the perception of the comb filter effects is reduced.

1. a) Erfassen eines akustischen Signals und Erfassen eines linearen und/oder eines rotatorischen Beschleunigungswertes eines Hörgerätes;
2. b) falls der lineare und/oder der rotatorische Beschleunigungswert größer als ein Schwellenwert ist, Anwenden einer Phasenmodulation auf das erfasste akustische Signal;
3. c) Verstärkung des erfassten akustischen Signals und Ausgabe über einen Receiver;
4. d) falls ein Abbruchkriterium, insbesondere ein bestimmter Schaltzustand eines Bedienelementes am Hörgerät, nicht erfüllt ist, Sprung zu Verfahrensschritt a).

The method according to the invention for operating a hearing device preferably comprises the following method steps:

1. a) detecting an acoustic signal and detecting a linear and / or a rotational acceleration value of a hearing aid;
2. b) if the linear and / or rotational acceleration value is greater than a threshold, applying phase modulation to the detected acoustic signal;
3. c) amplification of the detected acoustic signal and output via a receiver;
4. d) if an abort criterion, in particular a specific switching state of a control element on the hearing aid, is not met, jump to step a).

In the first method step, an acoustic signal and an acceleration value of the hearing device are detected, for example with a microphone of a hearing device. The detection of the acceleration value can be achieved, for example, by an acceleration sensor, can be measured by the linear accelerations, or by a gyrosensor, by the rotational movements and accelerations are measurable carried out, wherein the acceleration sensor can be arranged for example in the hearing aid. Accelerations are interpreted as head movements. If the linear and / or the rotational acceleration value is greater than a threshold value, the detected acoustic signal is subjected to a phase modulation, that is, the output of the acoustic signal in a later method step is delayed. The threshold value can be given in the unit m / s ² in the case of a linear acceleration sensor, and in the unit ° / s ² in the case of a rotary acceleration sensor. Conveniently, the threshold is obtained by series of measurements with subjects, such as the threshold corresponding to, for example, the average of the acceleration sensor signals instructing the subjects to keep their heads steady. In the next method step, the detected acoustic signal is amplified and output, taking into account the optionally modulated in the previous step phase on a receiver of the hearing aid. If an abort criterion is not met, the first step is jumped. The termination criterion can be, for example, the switching state "off" of an on-off switch on the hearing aid.

Preferably, the modulated phase is modulated by a noise function.

By a noise function, i. a function with a wide nonspecific frequency spectrum, the change in phase is uncorrelated. One can also speak of a jitter.

Conveniently, the modulated phase is modulated between 0 and 10 ms.

In an advantageous development, there is a positive correlation between the amplitude of the phase modulation and the output signal of the motion sensor.

A positive correlation in this context means that a large output signal of the motion sensor causes a large amplitude of the phase modulation.

In the case of a binaural supply of a hearing aid wearer, the method in the individual hearing aids is preferably carried out independently of one another.

This simulates the hearing situation of a person without a hearing aid, in which direct sound and reflected sound hits the listener's ears in an almost uncorrelated manner during head movements.

Another basic idea of the invention is a hearing device with a hearing device housing, at least one microphone, a receiver, an earpiece, a power supply unit and a signal processing unit, which comprises at least one motion sensor which is connected to the signal processing unit, wherein head movements of the hearing device wearer can be detected by the motion sensor and wherein the signal processing unit comprises means for modulating, upon detection of head movements of the hearing device wearer, the phase of an acoustic signal detectable by the microphone and amplifiable by the signal processing unit and deliverable by the receiver.

Thus, in addition to components such as hearing aid housing, microphone, receiver, ear piece, power supply unit and signal processing unit, the hearing aid according to the invention comprises as further component at least one motion sensor which can detect head movements of the hearing aid wearer and relay them in the form of measurement signals to the signal processing unit. The signal processing unit, such as an electronic computer or microcontroller, receives the motion sensor signals and is capable of modulating the phase of the acoustic signals detected by the microphone. Preferably, the signal processing unit of the hearing aid comprises means for carrying out one of the methods described above.

These include, for example, electronic, digital computers that can execute programs with digital signal processing steps.

In an advantageous embodiment of the hearing aid according to the invention, the motion sensor comprises at least one acceleration sensor and / or at least one gyrosensor.

An acceleration sensor measures the acceleration by determining the inertial force acting on a test mass. In practice, miniaturized sensors are often used whose measuring principle is based on piezoelectric effects. Other acceleration sensors are designed as so-called micro-electro-mechanical systems, MEMS. They are available in versions for measuring linear accelerations or for measuring angular accelerations.

In a further advantageous embodiment of the hearing aid according to the invention, the motion sensor comprises at least two acceleration sensors and / or at least two gyro sensors which are arranged in non-parallel axes, in particular in mutually orthogonally oriented axes.

Two or more acceleration sensors, which may also be components of an acceleration sensor component, allow the measurement of acceleration vectors in a two- or three-dimensional space. The prerequisite for this is that the measuring direction of the acceleration sensors is not parallel. For the measurement of a spatial acceleration vector, it is favorable to align the measuring directions orthogonal to one another. The same applies to the measurement of angular acceleration vectors in a two- or three-dimensional space.

The embodiments described in more detail below represent preferred embodiments of the present invention.

Fig. 1

ein Ausführungsbeispiel eines Hörgerätes nach dem Stand der Technik;

Fig. 2

ein Beispiel eines Frequenzgangs der Amplitude eines Kammfilters;

Fig. 3

ein Ausführungsbeispiel eines Ablaufdiagramms eines erfindungsgemäßen Verfahrens;

Fig. 4

ein Beispiel eines erfindungsgemäßen Phasenverlaufs über der Zeit;

Fig. 5

ein Ausführungsbeispiel eines erfindungsgemäßen Hörgerätes.

Further advantageous developments will become apparent from the following figures, including description. Show it:

Fig. 1

an embodiment of a hearing aid according to the prior art;

Fig. 2

an example of a frequency response of the amplitude of a comb filter;

Fig. 3

an embodiment of a flowchart of a method according to the invention;

Fig. 4

an example of a phase curve according to the invention over time;

Fig. 5

An embodiment of a hearing aid according to the invention.

FIG. 1 schematically shows a behind-the-ear hearing aid 1 'according to the prior art. It comprises a housing 2 'to be supported behind the auricle 12' of a hearing device wearer with a hearing device wearing hook 5 '. In the housing 2 ', in addition to electronic components, which are combined to form a signal processing unit 9', a microphone 3 ', a battery 8' and a receiver 4 'are arranged. The acoustic signal generated by the receiver 4 'is passed through the hearing device wearing hook 5' and a sound tube 6 'to an earpiece 7', which is inserted into an auditory canal 13 'of the hearing aid wearer. On the hearing aid housing 2 ', a control element 10', for example an on-off switch or a Betriebsmoduseinstellregler, arranged, which is connected to the signal processing unit 9 '.

In FIG. 2 an example of a frequency response 20 of a comb filter is shown. It shows the course of the amplitude 22, eg in decibels, above the frequency 21, eg in Hertz. Characteristic of a comb filter are the filter frequencies 24, also called notches, which occur several times and have the same frequency spacing 23. Between the filter frequencies 24, the gain increases up to the maxima 25, so that the comb-shaped amplitude curve 20, which gave this filter its name, results.

FIG. 3 shows an embodiment of a flowchart of a method 100 according to the invention. In the first method step 101, an acoustic signal and an acceleration value of the hearing device are detected, for example with a microphone of a hearing aid. Accelerations are interpreted as head movements. In the next method step, query 102 is performed as to whether the linear and / or the rotational acceleration value are greater than a threshold value. The threshold value is, for example, equal to the acceleration value with a quiet posture of the head. If the query 102 is satisfied, the detected acoustic signal is subjected to a phase modulation in method step 103, that is, the output of the acoustic signal is delayed in one of the following method steps. If the query 102 is not fulfilled, ie the acceleration value is less than or equal to the threshold value, the phase of the detected acoustic signal is not changed. In the next method step 104, the detected acoustic signal is amplified and output, taking into account the optionally modulated in the previous method step phase via a receiver of the hearing aid. In the next method step, query 105 is made as to whether an abort criterion has been met. The termination criterion can be, for example, the switching state "off" of an on-off switch on the hearing aid. Another termination criterion would be, for example, a change of the operating mode of the hearing aid. If the abort criterion is met, the method ends, otherwise the first method step 101 is jumped.

In FIG. 4 is an example of a phase curve 40 according to the invention over time 41, for example in milliseconds, shown, wherein the phase 42 is given for example in milliseconds. One recognizes in FIG. 4 two types of time ranges. During the time regions 45 no head movement of the hearing aid wearer is detected and thus no phase modulation is applied. The phase 46 is zero in the time ranges 45, ie no additional delay is added to the delay of the signal output inherently caused by the signal processing unit of the hearing aid. During the time range 43, a head movement of the hearing device wearer is detected. On the phase 44, a phase modulation, such as a noise function, applied.

In FIG. 5 Finally, an embodiment of a hearing aid 1 according to the invention is shown schematically. It comprises a housing 2 to be worn behind the auricle 12 of a hearing aid wearer with a hearing device wearing hook 5. In the housing 2, a microphone 3, a battery 8 and a receiver 4 are arranged in addition to electronic components that are combined to form a signal processing unit 9. The acoustic signal generated by the receiver 4 is passed through the hearing device wearing hook 5 and a sound tube 6 to an earpiece 7, which is inserted into an auditory canal 13 of the hearing aid wearer. On the hearing aid housing 2, a control element 10, for example, an on-off switch or a Betriebsmoduseinstellregler, arranged, which is connected to the signal processing unit 9. According to the invention, the hearing device 1 comprises a motion sensor 11, which is arranged in or on the hearing device housing 2 and, in the worn state of the hearing device 1, is exposed to the same accelerations as the head of the hearing device wearer. The motion sensor 11 includes, for example, three acceleration sensors that are orthogonal to each other and measure accelerations in the direction of the coordinate axes 16. Alternatively or additionally, the motion sensor 11 may include three gyro sensors that measure angular accelerations in the directions 15.

Claims (10)

Method (100) for operating a hearing aid (1), characterized in that a head movement of a hearing aid wearer is detected and amplified at a detected head movement, with a microphone (3) detected acoustic signal and phase-modulated with a receiver (4) is output , Method (100) for operating a hearing aid (1) according to claim 1, comprising the following method steps: a) detecting an acoustic signal and detecting a linear and / or a rotational acceleration value of a hearing aid (101); b) if the linear and / or rotational acceleration value is greater than a threshold (102), applying a phase modulation to the detected acoustic signal (103); c) amplification of the detected acoustic signal and output via a receiver (104); d) if an abort criterion, in particular a specific switching state of a control element (10) on the hearing aid (1), is not met (105), jump to step a). Method (100) for operating a hearing aid (1) according to one of the preceding claims, characterized in that the modulated phase is modulated by a noise function (44). Method (100) for operating a hearing aid (1) according to one of the preceding claims, characterized in that the modulated phase is modulated between 0 and 15 ms. Method (100) for operating a hearing aid (1) according to one of the preceding claims, characterized in that there is a positive correlation between the amplitude of the phase modulation and the output signal of the motion sensor. Method (100) for operating a hearing aid (1) according to one of the preceding claims, characterized in that in a binaural supply of a hearing aid wearer, the method (100) in the individual hearing aids (1) is performed independently. Hearing aid (1), comprising a hearing aid housing (2), at least one microphone (3), a receiver (4), an earpiece (7), a power supply unit (8) and a signal processing unit (9), characterized in that the hearing aid ( 1) comprises at least one motion sensor (11) which is connected to the signal processing unit (9), head movement of the hearing device wearer being detectable by the motion sensor (11), and wherein the signal processing unit (9) comprises means for detecting the head movements of the hearing device wearer Phase of an acoustic signal that is detectable by the microphone (3) and can be amplified by the signal processing unit (9) and by the receiver (4) can be emitted to modulate. Hearing aid (1) according to claim 7, characterized in that the signal processing unit (9) comprises means for carrying out a method (100) according to one of claims 1 to 5. Hearing aid (1) according to claim 7 or claim 8, characterized in that the movement sensor (11) comprises at least one acceleration sensor and / or at least one gyrosensor. Hearing aid (1) according to claim 7 or claim 8, characterized in that the movement sensor (11) comprises at least two acceleration sensors and / or at least two gyro sensors arranged in non-parallel axes, in particular in mutually orthogonally oriented axes (15, 16).

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