EP3275211A1

EP3275211A1 - Method for operating an electro-acoustic system and electro-acoustic system

Info

Publication number: EP3275211A1
Application number: EP16712305.8A
Authority: EP
Inventors: Stephan Ernst; Marko HIIPAKKA; Birger Kollmeier; Florian DENK
Original assignee: Carl Von Ossietzky Universitaet Oldenburg
Current assignee: Carl Von Ossietzky Universitaet Oldenburg
Priority date: 2015-03-26
Filing date: 2016-03-22
Publication date: 2018-01-31
Anticipated expiration: 2036-03-22
Also published as: US20180084328A1; DK3275211T3; WO2016150947A1; EP3275211B1; US10313778B2; DE102015003855A1

Abstract

The invention relates to a method for operating an electro-acoustic system (11), in which an electro-acoustic device (10) for occluding an ear canal is arranged on an ear, in which a signal processing device (16) for processing a signal incoming at the device (10) is used, and in which a correction unit (17) of the signal processing device (16) is used to modify the signal incoming at the device (10). In order to reduce, to avoid or to compensate for an interfering or undesired change in the perception of ambient noises during the use of an electro-acoustic device occluding the ear canal, the method is characterized in that, by means of the correction unit (17), a signal outgoing from the device (10) is generated in order to achieve acoustic transparency, in which, on the basis of the outgoing signal , a received signal is generated at the eardrum which is adapted so as to correspond to a free-ear received signal at the eardrum in the case of a free ear canal without the device (10).

Description

Method for operating an electroacoustic system and

electroacoustic system

Description

The invention relates to a method for operating an electroacoustic system in which an electroacoustic device for at least partially occluding an ear canal is at least partially disposed on an ear, wherein a signal processing device is used for processing a signal arriving at the device, and wherein the at least one correction unit the signal processing device is determined and / or used for modifying the signal arriving at the device. Furthermore, the invention relates to an electroacoustic system, which is operated by such a method.

Such a method and such an electro-acoustic system are known from US 2014/0321657 A1. Hereinafter, an incoming acoustic signal can be modified taking into account the acoustic properties of the auditory canal in a region between the device at least partially occluding the ear canal and the eardrum.

It is known electroacoustic systems and / or an electro-acoustic device, the ear and / or an ear canal at least partially or completely occlude, fill in, complete and / or seal, for example, in the field of consumer electronics and / or to use hearing aids. A disadvantage here is that the occlusion of the ear canal causes a change in the perception of ambient noise. This altered perception of, in particular natural, ambient noise may include attenuation, spectral modification, change in color tone, a change in the sound spectrum, and / or a change in spatial perception. It is particularly disadvantageous that ambient noises are not perceived and / or perceived as unnatural in an occluded auditory canal that is at least partially occluded by means of the electroacoustic device. This can lead to a danger to the person using the electroacoustic device, in particular in road traffic. In addition, the wearing and / or the use of the electro-acoustic device can be perceived as unpleasant. It is the object underlying the invention to develop such a method and an electro-acoustic system of the type mentioned above that a disturbing and / or undesirable change in the perception of ambient noise when using a the ear canal at least partially occluding electro-acoustic device reduces avoided and / or at least partially compensated.

The object underlying the invention is achieved by means of a method and an electroacoustic system of the type mentioned above, wherein by means of the at least one correction unit an outgoing signal from the device to achieve an acoustic transparency is generated in the due to the outgoing signal on the eardrum a received signal is generated, which is adapted according to a free-ear signal received at the eardrum at a free ear canal without the device. It is advantageous that ambient noise in spite of an at least partially occluded ear canal in sufficient quality are perceptible. In particular, the method and / or the electro-acoustic system makes it possible to control, control and / or manipulate the received signals, preferably a frequency response, on the eardrum. As a result, the electroacoustic system can be operated in an acoustic transparency mode. Preferably, the perception of ambient noise of a person using the electroacoustic system is not disturbed or changed at best, at least slightly and / or to a non-disturbing extent, due to the acoustic transparency. Preferably, the person using the electroacoustic system experiences a perception of noise, in particular approximately, as with a free auditory canal. Thus, the method and / or the electroacoustic system allows a more pleasant, in particular natural, perception of ambient noise in a partial and / or completely occluded ear canal. In this case, the electroacoustic system can enable a multiplicity of additional functions, for example in connection with consumer electronics, with hearing protection, with a hearing device and / or with a communication device, in particular a mobile telephone and / or a smartphone. In particular, a hearing aid may additionally be provided, preferably as needed. The received signal generated at the eardrum can be amplified and / or attenuated in comparison to the incoming signal at the device. In the context of the present application, the acoustic transparency is preferably designed as perceptual acoustic transparency. In particular, perceptual and / or acoustic transparency means that there is no audible difference to a free-ear signal or free-ear received signal. Thus, a perceptive and / or acoustic transparency can be achieved without having to achieve an absolute physical agreement of the generated received signal on the eardrum with a free-ear received signal at a free auditory canal without the device. Preferably, it is sufficient for a person using the device to have the perception that the received signal generated by the device is in perceptual coincidence with the free-ear received signal at a free auditory canal without the device.

According to a further embodiment, the correction unit has a first correction filter and a second correction filter. The first correction filter of the signal processing device can be determined and / or used to achieve the acoustic transparency. The second correction filter of the signal processing device is preferably determined and / or used for modifying the signal, in particular the acoustic signal, which is emitted by the device. In particular, the acoustic properties of an ear canal section from the device to a eardrum of the ear are taken into account by means of the second correction filter. The first correction filter and / or the second correction filter can be designed as, in particular digital, electrical circuits. The correction unit, the first correction filter and / or the second correction filter can have at least one analog-to-digital converter and / or at least one digital-to-analog converter.

Preferably, a first correction filter of the correction unit is connected upstream of a second correction filter of the correction unit. In particular, the incoming signal is first modified by means of the first correction filter to achieve the acoustic transparency. Subsequently, the changed incoming and / or received signal by means of the second correction filter for filtering out of transmission effects in the range from the device to the eardrum due to the at least partial occlusion of the ear canal by means of the device modified. Preferably, by means of the outgoing from the device, in particular acoustic signal, a received signal is generated, which corresponds to the free-ear received signal at a free auditory canal without the device. Thus, a disturbing influence of the ear canal at least partially occluding device on the perception of ambient noise can be reduced and / or compensated. In particular, to achieve the acoustic transparency due to the outgoing signal in the region of the ear canal portion of the device to the eardrum, a received signal is generated, which is adapted according to a free-ear signal received in this area of the ear canal section at a free ear canal without the device and / or this corresponds.

According to a development, the incoming, in particular acoustic, signal is supplied to the signal processing device by means of an external sound receiver assigned to the device and directed away from the eardrum and outwards as an incoming electrical signal. Preferably, at least one additional external acoustic and / or electrical signal is supplied to the signal processing device, in particular by means of an additional external sound receiver and / or a direct line connection with an additional external signal source. In particular, the outer sound receiver and / or the additional outer sound receiver are each designed as a microphone. The additional external signal can also be modified by means of the correction unit.

In particular, by means of the electroacoustic system, a negative feedback loop can be realized. Preferably, the external sound receiver and the additional external sound receiver are used to implement the negative feedback loop.

In another embodiment, calibration is performed prior to using the electroacoustic system. In particular, a first correction filter and / or a second correction filter is determined as part of the calibration. Preferably, the calibration is performed after each insertion of the device for at least partial occlusion of the ear canal. Particularly preferably, the calibration is performed by means of an external sound source and / or a calibration control. Alternatively, initially a start calibration for determining the first correction filter and the second correction filter, in particular by means of an external sound source, can be performed. After the start calibration has been carried out and a renewed onset of the device for at least partially occluding the auditory canal, only a single correction filter, in particular the first correction filter or the second correction filter, is recalibrated within the scope of a partial calibration. As an external sound source for calibration, a headphone can be used, which is placed on an auricle with an inserted electro-acoustic device becomes. In particular for detecting the spatial resolution of an incoming signal, the use of a signal striking the outside of the ear is advantageous. The calibration control may be in the device, an ear piece, a computer and / or a smartphone. In particular, the calibration controller has a processor. The calibration controller may be connected to the electroacoustic device by means of a cable, a wireless connection, a near field communication and / or Bluetooth.

Preferably, an individual calibration is carried out for the respective person using the device and / or after each insertion of the device into the auditory canal. In particular, a calibration and / or adjustment of the first and / or second correction filter during operation is performed. As a result, a readjustment can be realized. Preferably, a readjustment takes place if at least one predetermined triggering parameter is given. For example, a readjustment can take place at predetermined times or at predetermined time intervals. Alternatively or additionally, a readjustment can be initialized if at least one predetermined and monitored triggering parameter is reached, undershot or exceeded. In particular, the correction unit, the first correction filter and / or the second correction filter is recalibrated during operation and / or tracked. Thus, a continuous and / or discontinuous calibration, in particular in conjunction with a start and / or Erstkalibrierung occur. Preferably, a first correction filter of the correction unit is determined on the basis of a first model and / or a second correction filter of the correction unit on the basis of a second model. Preferably, the first model and / or the second model is based on the Thevenin equivalent and / or the Norton equivalent. These models are proven and allow a sufficiently accurate estimation of the relevant parameters.

According to a further development, a total pressure P _to t of an external acoustic signal within the auditory canal at least partially occluded with the device for determining a first correction filter A of the correction unit is composed of two parts. Preferably, a first part of the total pressure P _to t is a passage pressure mittels _Η τ measured by means of an inner sound receiver assigned to an eardrum and facing an eardrum of the ear. The inner sound receiver can be designed as a microphone. In particular, the passage pressure Ρ _Η τ is a sound pressure of an external acoustic signal after passing through the ear canal at least partially occluded with the device. Preferably, a second part of the total pressure P _to t is a sound generator associated with one of the apparatus and facing the eardrum outgoing pressure P _E p. The sound generator can be designed as a loudspeaker and / or receiver. At least one additional and / or additional sound generator may be provided. The at least one additional sound generator may be arranged at an end which is attached to the eardrum or at an end of the device remote from the eardrum.

Preferably, in the context of the present invention, a pressure is understood to mean a pressure frequency. In particular, due to a print frequency of a signal source, a noise source and / or a sound generator, a print frequency response results at a sound receiver and / or an eardrum.

According to a further embodiment, for determining a first correction filter A of the correction unit, a total pressure P _to t of an external acoustic signal within the auditory canal at least partially occluded with the device is equated with an expected target pressure P _T , E. The first correction filter A is preferably determined by taking into account a throughput pressure Ρ _Η τ measured by means of an inner sound receiver assigned by means of one of the devices and facing an eardrum of the ear with the following equation:

Ptot ~ PHT

In particular, after a first determination of a first correction filter A of the correction unit, in particular as part of a calibration, a fine adjustment of the first correction filter A is performed. Preferably, at least one predetermined calibration signal and / or a predetermined noise is used. The calibration signal may be formed as a white noise. In particular, in the fine adjustment, a pressure P _E measured by means of one of the apparatuses and associated with an eardrum of the ear facing the inner sound receiver is compared with a target pressure P _T , E at the position of the inner sound receiver. In this case, the first correction filter A can be iteratively adjusted in the event of a deviation of the measured pressure P _E from the target pressure P _T , E until a predefined convergence criterion has been reached.

Preferably, for determining a first correction filter A of the correction unit, a pressure P _E measured by means of one of the device and facing an eardrum of the ear is equated with an expected target pressure P _T, E at the inner sound receiver, the expected target pressure P _T , E at the inner sound receiver is estimated as a pressure at the location of the inner sound receiver at a free auditory canal without the device. The expected at a free auditory canal target pressure P _T, E at the inner sound receiver can be estimated by means of an electro-acoustic model, in particular with a Thevenin pressure source model and / or a source-impedance model. Preferably, the expected target pressure P _{T, E} at the inner sound receiver is estimated by means of a source pressure P _S , an auditory canal impedance Z _L and a radiation impedance Z _R A _D , in particular with the following equation:

According to a further development, an estimation of the acoustic received signal on the eardrum is carried out for determining a second correction filter B of the correction unit by means of an inner sound receiver assigned to the device and facing an eardrum of the ear. In particular, an equal frequency response and / or an equal pressure at the inner sound receiver and at the eardrum is assumed for the estimation. Preferably, the pressure at the eardrum P _D is estimated by means of the pressure PE measured at the inner sound receiver using an electroacoustic model of the auditory canal.

Preferably, a pressure at the eardrum P _{D is determined} by means of a pressure P _E measured at the inner sound receiver and by means of the correction filter B with the following equation:

P _D = PE B

Thus, the second correction filter B can be determined by knowing the pressure at the eardrum PD and the pressure P _E measured at the inner sound receiver. The electroacoustic system with the electroacoustic device for at least partially occluding an auditory canal, in particular for realizing the method according to the invention, preferably has the signal processing device for processing a signal arriving at the device. In this case, the signal processing device has at least one correction unit for modifying the signal arriving at the device. Furthermore, the correction unit is used for providing and / or generating a signal that goes out of the device. The correction unit has a first correction filter and a second correction filter, wherein the first correction filter of the signal processing device is designed to achieve an acoustic transparency in which due to the outgoing signal at the eardrum, a received signal can be generated, corresponding to a free-ear signal received at the eardrum at a free ear canal without the device is adjusted. Preferably, the second correction filter of the signal processing device is designed to modify the outgoing of the device, in particular acoustic, signal. Of particular advantage is the use of a method according to the invention and / or an electroacoustic system according to the invention, in particular in connection with hearing protection, in-ear headphones and / or a hearing aid. The method according to the invention and / or the electroacoustic system can be used in conjunction with consumer electronics and / or with a communication device, in particular a mobile telephone and / or a smartphone. In particular, the method and / or electroacoustic system is integrated with an existing system and / or devices, such as a hearing aid, in-ear headphone, in-the-ear hearing aid , a hearing aid, a behind-the-ear device and / or a communication device. An external and / or additional, in particular acoustic, signal can be mixed with an environmental signal of ambient noise. In particular, the mixture is applied after the application of the first correction filter to the incoming signal and / or the ambient signal.

The signal processing device can be integrated in an in-ear device, a behind-the-ear device, a computer and / or a communication device, in particular in a mobile telephone and / or smartphone. Preferably, the inner sound receiver, the outer sound receiver and / or the sound generator by means of a line with an in-ear device, a behind-the-ear device, a computer and / or a communication device, in particular in a mobile phone and / or smartphone , connected.

The acoustic transparency may allow a perception of ambient sounds, which is familiar at least largely to a person, and / or a spatial hearing in a partially occluded auditory canal.

According to a further embodiment, the electroacoustic system, the correction unit, the first correction filter and / or the second correction filter for attenuating and / or suppressing a sound radiation to the outside, in particular from the person using the device and / or the eardrum away formed.

The electroacoustic device may comprise a venting device. The venting device can be designed as a ventilation duct in order to allow a pressure compensation in a device inserted into an auditory canal. As a result, the wearing comfort can be further improved. The device and / or an earpiece may comprise an air-permeable material. An internal sound receiver, an external sound receiver and / or a sound generator may be arranged at least partially or completely within the ventilation device.

The invention will be explained in more detail with reference to the figures. Show it:

1 is a schematic representation of an electroacoustic device for an inventive electroacoustic system,

FIG. 2 shows a schematic illustration of an electroacoustic model of the electroacoustic device according to FIG. 1, FIG.

3 shows a schematic representation of a logic circuit of a signal processing with the electroacoustic device according to FIG. 1 during a calibration, and FIG

4 shows a schematic representation of a logic circuit of a signal processing device of the electroacoustic device according to FIG. 1.

1 shows a schematic representation of an electroacoustic device 10 for an inventive electroacoustic system 11. The device 10 has an earpiece 12. In this embodiment, the earpiece 12 is adapted in shape to an individual auditory canal of a person not shown here. Alternatively, at least one outer coating of the ear piece 12 may be formed elastically, whereby at least a partial adaptation of the surface of the ear piece 12 is made possible to the shape of an ear canal. The earpiece 12 may be placed in an inner auricle shell and / or an auditory canal entrance. By means of the ear piece 12 of the ear canal is at least partially, ie partially or completely, occluded.

The device 10 has an external sound receiver 13. In this embodiment, the external sound receiver 13 is formed as an external microphone. When the earpiece 12 is inserted in an ear and / or ear canal, the external sound receiver 13 is directed away from an eardrum not shown here. The external sound receiver 13 is directed outwardly for receiving an incoming signal, namely ambient acoustic noise. Here, the outer sound receiver 13 is arranged by way of example in the surface of the ear piece 12. The location of the outer sound receiver 13 allows the incoming signal to be all spatial contains monaural information. By means of the external sound receiver 13 incoming acoustic signals are converted into electrical signals.

Furthermore, the device 10 has an inner sound receiver 14. In this embodiment, the inner sound receiver 14 is formed as an inner microphone. If the earpiece 12 is inserted in an ear and / or an ear canal, the inner sound receiver 14 faces an eardrum not shown here. The inner sound receiver 14 is directed inwardly for detecting a sound field in an ear canal portion of the device 10 and the earpiece 12 to the eardrum. Here, the inner sound receiver 14 is arranged by way of example in the surface of the ear piece 12. By means of the inner sound receiver 14 incoming acoustic signals are converted into electrical signals. The device 10 has a sound generator 15. The sound generator 15 is arranged in the region of the inner sound receiver 14. Furthermore, the sound generator 15 faces an eardrum not shown here, when the earpiece 12 is inserted in an ear and / or an ear canal. Here, the sound generator 15 is arranged by way of example on the surface of the ear piece 12. The sound generator 15 is directed inwardly to radiate the outgoing signal into the ear canal portion between the device 10 and the earpiece 12 and the eardrum. The sound generator 15 is designed to convert an electrical signal into an acoustic signal. The device 10 has a signal processing device 16. The outer sound receiver 13, the inner sound receiver 14 and the sound transducer 15 are each connected to the signal processing device 16 by means of a line. The signal processing device 16 is integrated in the ear piece 12 in this embodiment. Alternatively, the signal processing device 16 may also be arranged outside the ear piece 12, for example in a housing for placing behind an ear or in an auricle. Here, the signal processing device 16 is embodied by way of example as a digital signal processing device 16. The signal processing device 16 has analog-to-digital converters and digital-to-analog converters which are connected to electroacoustic transducers, in particular to the external sound receiver 13, the inner sound receiver 14 and the sound transducer 15. By means of the signal processing device 16, calculations, modifications and / or or making corrections with respect to a signal input to the external sound receiver 13 and a signal output from the sound generator 15.

The signal processing device 16 has a correction unit 17. By means of the correction unit 17 is a on the device 10 and the outer sound receiver Corrected 13 and / or modified incoming signal to produce an outgoing from the device 10 and the sound generator 15 signal. The correction unit 17 has a first correction filter A and a second correction filter B. In this exemplary embodiment, the signal processing device 16 is connected by means of a line to an additional external signal source 18. By means of the additional signal source 18, an additional external, in particular acoustic, signal of the signal processing device 16 can be fed. The additional signal source may be formed as a consumer electronics, a music source and / or a communication device.

The device 10 or the earpiece 12 has a venting device 19. The venting device 19 is formed in this embodiment as a ventilation duct. The venting device 19 allows for a device used in an auditory canal 10 a pressure equalization. An air volume of an ear canal portion between the earpiece 12 and the eardrum is connected by means of the venting device 19 with the environment outside the ear canal or the ear. The inner sound receiver 14 allows for an at least partially occluded by means of the device 10 and the earpiece 12 ear canal an estimate of a received signal and / or an acoustic signal on the eardrum, in particular a frequency response to the eardrum due to any noise source. This estimation can be made by assuming the mechanical-acoustic properties of the device 10 such that the frequency response at the position of the inner sound receiver 14 and the eardrum are the same. In this embodiment, the pressure on the eardrum is estimated by means of the pressure measured at the position of the inner sound receiver 14 using an electroacoustic model of the ear canal P.

FIG. 2 shows a schematic representation of an electroacoustic model 20 of the electroacoustic device 10 according to FIG. 1. The device 10 or the earpiece 12 according to FIG. 1 is modeled as a Norton and / or Thevenin equivalent electroacoustic velocity and / or pressure model , which is connected to the ear canal impedance as shown in FIG.

The source parameters are applied to an electroacoustic circuit model having a voltage source for the pressure or a current source for the velocity, an internal source impedance, the ear canal as a two-port and the eardrum as the terminating impedance of the circuit. The source terms P _s for the pressure, Q _s for the speed and Z _s for the impedance are by means of measurements the impulse responses induced by the sources when connected to different loads of known theoretical impedances. Therefore, these are assumed to be known and are part of the electroacoustic ear canal model P, which depends on the individual design of the device 10. The abbreviation P _L in FIG. 2 stands for the load pressure and the abbreviation Z _L for the load impedance.

The load impedance Z _L is determined by means of the pressure P _E measured at the position of the inner sound receiver 14 and using the electroacoustic circuit model according to FIG. 2 with the following formula:

When the source impedance Z _S , the load impedance of the ear canal Z _L , in particular in a region from the device 10 or the earpiece 12 to the eardrum, and the pressure P _E present in the interior of the auditory canal and / or a pressure-frequency response are known the particle velocity U _E at the position of the inner sound receiver 14 using the load impedance Z _L according to FIG and / or using the source impedance Z _S according to certainly.

The relationship of a pressure at the eardrum P _D to the pressure P _E at the position of the inner sound receiver 14 is given according to the energy density based estimation method, as described for example in the following document:

M. Hiipakka, M. Karjalainen and V. Pulkki, "Estimating pressure at eardrum with pressure-velocity measurements from the ear canal entrance", Application of Signal Processing to Audio and Acoustics, 2009. WASPAA '09, IEEE Workshop on., 2009. The measured pressure P _E at the position of the inner sound receiver 1 and the estimated particle velocity U _E are used to obtain the following estimate:

Here, p is the air density and c is the speed of sound.

The ratio of P _E to P _D is converted into the linear filter B, giving the following equation:

P _D = P _E B

By means of the filter B, the acoustic properties of the ear canal, in particular in a region between the ear canal at least partially occluding device 10 and the eardrum end facing the earpiece 12, in the modification or correction by the signal processing means 16 and the correction unit 17 are taken into account ,

FIG. 3 shows a schematic representation of a logic circuit 21 for signal processing with the electroacoustic device 10 according to FIG. 1 during a calibration.

The electroacoustic system 11, the device 10 or the earpiece 12 can be calibrated in situ, that is to say in the case of an at least partially occluded auditory canal. The aim of the calibration is to obtain a predetermined pressure and / or frequency response on the eardrum using a calibration routine. For this purpose, the filter A is determined. By means of the filter A, a signal which originates from the device 10 or the sound generator 15 by modifying the incoming signal can be generated, which generates a target pressure and / or a target frequency response at the position of the inner sound receiver 14.

Thus, the pressure P _E at the position of the inner sound receiver 14 corresponds to the target pressure ΡΤ, Ε at the position of the inner sound receiver 14:

^P E = ^P T, E The pressure P _E or the target pressure P _TE at the position of the inner sound receiver 14 results from a noise source 22 due to an ambient noise signal. The noise source 22 is outside the ear and causes ordinary ambient noise. As shown in FIG. 3, the acoustic signal emanating from the noise source 22 is divided into two sub-signals 23, 24 within the auditory canal and when the auditory canal is at least partially occluded by means of the device 10 or the earpiece 12.

The first sub-signal 23 is a transit signal. The first part signal 23 is associated with a pressure frequency response and / or a passage pressure Ρ _Η τ, which is measured at the position of the inner sound receiver 14. The second sub-signal 24 is a device output signal. The second partial signal 24 is generated and emitted by the earpiece 12 in the direction of the eardrum by means of the sound generator 15. The second partial signal 24 results from the signal arriving at the outer sound receiver 13, which is modified by means of the filtering by means of the first filter A and the second filter B and is subsequently emitted by means of the sound generator 15. The second partial signal 24 is assigned an outgoing pressure frequency and / or an outgoing pressure P _E p.

For calibration, using the noise source 22, which is designed as a headphone in this embodiment, when not using the filters A and B, the passage pressure Ρ _Η τ and the outgoing pressure P _E p by means of the sound receiver 13, 14 is measured. However, since the outgoing pressure P _{EP is} not measurable independently of the passage pressure Ρ _Η τ, an overall frequency response and / or a total pressure P _{tot is} introduced:

^P tot- ^P EP + HT

Taking into account the correction filter A, the total pressure P _to t is set equal to the target pressure P _T , E:

^P T, E- ^P HT + ^P EpA-PHT + iPtot ~ ^P HT) A

Thus, after the first determination described above, a correction filter A is calculated by means of the measured frequency responses and / or pressures P _T and P _tot as follows:

This first correction filter A is determined as part of an initial calibration.

Subsequently, a fine adjustment of the correction filter A can be performed. To the actual frequency response and / or the pressure P _E at the inner sound receiver 14 _to adjust _E to the target pressure P _T, is used a predetermined calibration signal. In this embodiment, the calibration signal is formed as white noise. The calibration signal is output from the noise source 22. By means of the inner sound receiver 14, the frequency response and / or the pressure P _{E is} measured. Due to a deviation of the measured pressure P _E from the target pressure P _{T, E} , the correction filter A is adjusted accordingly. The first correction filter A is iteratively adjusted in a deviation of the measured pressure P _E of the target pressure Ρ _Τ, Ε until reaching a predetermined convergence criterion.

For determining the correction filter A or for achieving the acoustic transparency, the target pressure Ρ _{Τ, Ε} at the position of the inner sound receiver 14 must be known. Furthermore, the frequency response must be generated and / or the pressure P _D at the eardrum for a free ear canal and an at least partially occluded ear canal with an active and calibrated device 10 be the same. Accordingly, the pressure P _D on the eardrum equals the target pressure P _{T, D} on the eardrum:

? D ⁼ PT, D is hereby established a target model T to get ready to adjust the frequency response and / or the pressure at the eardrum as an individual assessment for each device 10 person using.

In this case, however, the frequency response and / or the target pressure P _T , _D on the eardrum is not determined or estimated. Instead, the target frequency response and / or the target pressure P _{T, E} at the position of the inner sound receiver 14 at a free auditory canal is estimated.

For this purpose, an electro-acoustic circuit model is used, which has a Thevenin pressure source model P _s and a source impedance model Z _s . The source pressure P _s is estimated by means of the frequency response measured at the outer sound receiver 13 and / or the pressure measured there, when an incoming signal is generated by the noise source 22. The radiation of the source pressure P _s into the auditory canal in the case of a free auditory canal is estimated by means of the radiation impedance Z _RA D and the auditory canal impedance Z _L.

The individual ear canal impedance Z _L , which depends on the respective person, is determined by means of the above-mentioned measurements and calculations. However, no individual measurements and / or determinations for the radiation impedance Z _{RAD are} possible. Therefore, an estimated value is used based on a theoretical model and measurements with subjects, as described for example in the following document:

M. Hiipakka, T. Kinnari and V. Pulkki; "Estimating head-related transfer functions of human subjects from pressure-velocity measurements", The Journal of the Acoustic Society of America, 2012.

This results in the target frequency response and / or the target pressure P _T , E at the position of the inner sound receiver 14 with a free auditory canal as follows:

In this embodiment, the calibration described above for determining the first correction filter A and the second correction filter B is carried out after each insertion of the device 10 or the earpiece 12 into the ear or the auditory canal. As a result, changes due to a deviating position of the device 10 or the earpiece 12 in the auditory canal or at the ear are taken into account. As a result, an acoustic transparency with a particularly high quality can be achieved. After calibration or in normal operation of the device 10 or the ear piece 12, the correction filters A and B remain unchanged according to this embodiment. Alternatively, an adaptive tracking and / or recalibration of the correction filter A and / or B, in particular during normal operation, take place.

After calibration, the first correction filter A is used to modify the incoming signal, thereby modifying the outgoing signal or outgoing pressure P _E p. By means of the second correction filter B, information about the transmission path from the position of the inner sound receiver to the eardrum is taken into account in the modification of the signal arriving at the device 10 or in the generation of the outgoing signal.

FIG. 4 shows a schematic representation of a logic circuit 25 having a signal processing device 16 of the electroacoustic device 10 according to FIG. 1.

In normal operation, an ambient noise is received as an incoming acoustic signal from the external sound receiver 13, converted into an incoming electrical signal and sent to the signal processing device 16. The signal processing device 16 corrects and modifies the signal by means of the two correction filters A and B in order to match the frequency response and / or the pressure on the eardrum to the frequency response and / or the pressure at the eardrum adjust the free auditory canal. In this embodiment, due to the two correction filters A and B the same frequency response and / or the same pressure on the eardrum is generated as in a free auditory canal. Such acoustic transparency is made possible because the incoming signal on the outer sound receiver 13 contains all the direction information. In contrast, the transmission path from the inner auricle to the eardrum for both the free and the at least partially occluded ear canal is independent of the incoming signal direction or direction of sound.

According to FIG. 1 and FIG. 4, an additional signal to an additional signal source 18 of the device 10 is supplied to the ambient noise, for example from the noise source 22 according to FIG. 3. For example, the additional signal source 18 is designed as a consumer electronics and / or as an additional sound receiver for the device 10. Depending on the purpose and / or the nature of the signal source 18, the additional signal is used to convey information and / or supplement the incoming signal at the device 10. The frequency response and / or the pressure on the eardrum due to the additional signal or the additional signal source 18 is modified in this embodiment by means of the previously determined correction filters A and / or B. Due to a correction by means of the correction filter B, the additional signal is modified such that unwanted transmission effects of the ear canal in a region between an eardrum-facing end of the device 10 and the earpiece 12 and the eardrum are attenuated and / or avoided.

B eq u c ia l e s:

10 electroacoustic device

1 1 electroacoustic system

12 ear piece

13 outer sound receiver

14 inner sound receiver

15 sound generators

16 signal processing device

17 correction unit

18 additional signal source

19 venting device

20 electroacoustic model

21 logical circuit

22 noise source

23 first partial signal

24 second partial signal

A first correction filter

B second correction filter

P ear canal model

T target model

Ps source pressure

Q's source speed

Z _s source impedance

z _L Load or ear canal impedance

PL load pressure

PE pressure on the inner sound receiver

u _E particle velocity at the inner sound receiver

PD pressure on the eardrum

P air density

c speed of sound

PT, D Target pressure on the eardrum

Ρτ, Ε target pressure on the inner sound receiver

Ptot total pressure

PHT through pressure at the inner silencer

PEP outgoing pressure

ZRAD radiation impedance

Claims

P a t e n t a n c e rs:

Method for operating an electroacoustic system (11), in which an electroacoustic device (10) for at least partially occluding an auditory canal is arranged at least partially on an ear, wherein a signal processing device (16) for processing a signal arriving at the device (10) is used, and in which at least one correction unit (17) of the signal processing device (16) for modifying the device (10) incoming signal is determined and / or used, characterized in that by means of the at least one correction unit (17) one of the device (10) outgoing signal for achieving an acoustic transparency is generated in which due to the outgoing signal on the eardrum, a received signal is generated, which is adapted according to a free-ear signal received at the eardrum at a free auditory canal without the device (10) ,

Method according to Claim 1, characterized in that the correction unit (17) has a first correction filter (A) and a second correction filter (B), wherein the first correction filter (A) of the signal processing device (16) determines and / or is preferably used, the second correction filter (B) of the signal processing device (16) for modifying the device (10) outgoing, in particular acoustic, signal is determined and / or used, in particular by means of the second correction filter (B) the acoustic properties of a Auditory canal portion of the device (10) taken up to a tympanic membrane of the ear.

A method according to claim 1 or 2, characterized in that a first correction filter (A) of the correction unit (17) is preceded by a second correction filter (B) of the correction unit (17), in particular the incoming signal is first by means of the first correction filter (A) for Achieving the acoustic transparency is modified and subsequently the modified incoming signal is modified by means of the second correction filter (B) for filtering out transmission effects in the area from the device (10) to the eardrum due to the at least partial occlusion of the auditory canal by means of the device (10), preferably is generated by the device (10) outgoing, in particular acoustic, signal, a received signal corresponding to the free-ear-received signal at a free auditory canal without the device (10).

Method according to one of the preceding claims, characterized in that the incoming, in particular acoustic, signal by means of one of the device (10) associated and away from the eardrum and outwardly directed external sound receiver (13) is supplied as an incoming electrical signal to the signal processing means (16), preferably at least one additional external acoustic and / or electrical signal of the signal processing means (16 ), in particular by means of an additional external sound receiver and / or a direct line connection with an additional external signal source (18) supplied, particularly preferably the additional external signal is modified by means of the correction unit (17).

Method according to one of the preceding claims, characterized in that before the use of the electroacoustic system (11) calibration is performed, in particular, a first correction filter (A) and / or a second correction filter (B) is determined, preferably carried out in the context of calibration the calibration after each insertion of the device (10) for at least partially occluding the ear canal, more preferably, the calibration is performed by means of an external sound source (22) and / or a calibration control.

Method according to one of the preceding claims, characterized in that a first correction filter (A) of the correction unit (17) on the basis of a first model and / or a second correction filter (B) of the correction unit (17) is determined on the basis of a second model Preferably, the first model and / or the second model is based on the Thevenin equivalent and / or the Norton equivalent.

Method according to one of the preceding claims, characterized in that a total pressure (P _to t) of an external acoustic signal within the at least partially occluded auditory canal with the device (10) for determining a first correction filter (A) of the correction unit (17) consists of two Preferably, a first part of the total pressure (P _to t) is a passage pressure (Ρ _Η τ) measured by means of an internal sound receiver (14) assigned to an eardrum of the ear and / or is a second part of the Total pressure (Ptot) a by means of one of the device (10) associated and the eardrum facing sound generator (15) outgoing pressure (P _EP ).

Method according to one of the preceding claims, characterized in that for determining a first correction filter (A) of the correction unit (17) a total pressure (P _to t) of an external acoustic signal within the at least partially occluded with the device (10) The auditory canal is equated with an expected target pressure (P _TE ), preferably the first correction filter (A) is measured taking into account a throughput pressure (Ρ _Η τ) assigned to one of the devices (10) and facing an eardrum of the ear. determined by the following equation:

Method according to one of the preceding claims, characterized in that after a first determination of a first correction filter (A) of the correction unit (17), in particular as part of a calibration, a fine adjustment of the first correction filter (A) is performed, preferably at least one predetermined calibration signal and In particular, during fine adjustment, a pressure (P _E ) measured by means of an apparatus (10) and associated with an eardrum of the ear facing the inner sound receiver (14) is compared with a target pressure (P _T , E) the first correction filter (A) is iteratively adjusted in the event of a deviation of the measured pressure (P _E ) from the target pressure (P _T , E) until a predetermined convergence criterion has been reached.

Method according to one of the preceding claims, characterized in that for determining a first correction filter (A) of the correction unit (17) a pressure (P _E ) measured by means of one of the device (10) and associated with an eardrum of the ear facing the inner sound receiver (14) is equated with an expected target pressure (P _T, E) at the inner sound receiver (14), wherein the expected target pressure (ΡΤ, Ε) at the inner sound receiver (14) as a pressure at the location of the inner sound receiver (14) at a free Auditory canal without the device (10) is estimated.

A method according to claim 10, characterized in that the expected target pressure (P _T , E) at the inner sound receiver (14) by means of an electro-acoustic model, in particular with a Thevenin pressure source model and / or a source-impedance model is estimated Preferably, the expected target pressure (P _T , E) at the inner sound receiver (14) is estimated by means of a source pressure (P _S ), an auditory canal impedance (Z _L ) and a radiation impedance (ZRAD), in particular with the following equation:

^P T, E - ^P S Method according to one of the preceding claims, characterized in that for determining a second correction filter (B) of the correction unit (17) by means of one of the device (10) associated and an eardrum of the ear facing inner sound receiver (14) an estimate of the acoustic received signal on the eardrum In particular, an equal frequency response and / or an equal pressure at the inner sound receiver (14) and at the eardrum is assumed for the estimation, preferably the pressure at the eardrum (P _{D) is determined} by means of the pressure measured at the inner sound receiver (14) ( P _E ) using an electroacoustic model of the ear canal.

Method according to one of the preceding claims, characterized in that a pressure at the eardrum (P _D ) is determined by means of a pressure (P _E ) measured at the inner sound receiver (14) and by means of the correction filter (B) with the following equation:

P _D = PE β

An electroacoustic system having an electroacoustic device (10) for at least partially occluding an ear canal of an ear, characterized by an operation with a method according to any one of the preceding claims.

An electroacoustic system having an electroacoustic device (10) for at least partially occluding an ear canal, in particular for realizing a method according to one of claims 1 to 13, comprising signal processing means (16) for processing a signal arriving at the device (10), the signal processing means (16) at least one correction unit (17) for modifying the signal arriving at the device (10) and for providing a signal leaving the device (10), characterized in that the correction unit (17) comprises a first correction filter (A) and a second correction filter (B), wherein the first correction filter (A) of the signal processing device (16) is designed to achieve an acoustic transparency, in which due to the outgoing signal on the eardrum, a received signal can be generated, which corresponds to a free-ear received signal am Eardrum with a free Gehö is adapted without the device (10), preferably the second correction filter (B) of the signal processing device (16) for modifying the device (10) outgoing, in particular acoustic, signal is formed.

16. Use of a method according to any one of claims 1 to 13 and / or an electro-acoustic system (11) according to claim 14 or 15, in particular in connection with an ear protection, an in-ear headphones and / or a hearing aid.