EP1519618A1 - Method and communication equipment with means for audio signals interference suppression - Google Patents

Abstract

The operating method has audio signals (8.1-8.3) transmitted by the communications device (13.1,13.2), with reception of the audio signals after reflection, for determining an algorithm (5) corresponding to the pulse response of the environment (9), the superimposed noise components resulting from the environment within audio signals (15.1-15.3) received from an external sound source, e.g. the user of the communications device (15), compensated via a corresponding noise suppression algorithm (16). An independent claim for a communications device with audio signal noise suppression is also included.

Description

The invention relates to a method for operating a communication device, wherein the communication device audio signals radiates to an environment and on the one hand these audio signals including environmental superimposed interference components, which contain at least echo and reverberation, resumes and on the other hand audio signals of an external sound source, preferably a communication device user, including whose environmental disturbances, absorbs, and the resumed audio signals by a first algorithm used to provide a room impulse response to the environment determine.

Furthermore, the invention relates to a communication device with means for interference suppression of audio signals, wherein the communication device has at least one speaker, the audio signals radiates to an environment and continue at least a microphone, with the one hand, these audio signals including environmental layered Noise components that contain at least echo and reverberation again be recorded and on the other hand audio signals a external sound source, preferably a communication device user, including their environmental disturbances, be received, and in the communication device a first Is provided, which is a means of calculating a Room impulse response of the environment has.

It is well known that radiated over loudspeakers or from a sound source, for example the human Voice, in general, produced audio signals in rooms Echoes and reverberation are falsified. While the echoes off direct, simple and early reflections of the audio signal at one of the boundary surfaces of the room, for example the Walls, the floor or the ceiling, is the reverberation diffuse and becomes by multiple, only after statistical Methods estimable reflections at the boundary surfaces generated.

The type and duration of the reverberation are determined by the geometry of the Space and the condition of the walls. Various algorithms of digital voice and speech Audio signal processing, especially those dealing with need to deal with the problem of reverberation of speech signals often an estimate of the so-called reverberation time. The reverberation time, usually abbreviated to T60, is one in the Acoustics known important characteristic for rooms. It can be frequency-dependent be determined and describes in what time after silencing a signal source, the energy of the Hall signal by 60 dB [dB = decibels], possibly still dependent from the respective frequency band has fallen off.

The reverberation time has hitherto been determined by two types of processes, namely statistical statistical methods or by a method that uses one or more measuring signals.

In the first case, for example, one over many speakers and Language examples averaged information about the time and Amplitude ratio of speech sections to speech pauses used to discuss the change of this ratio in the Compared to the value of unvoiced speech a statement about to gain the reverberation time.

It is easy to see that here spokespecific peculiarities, such as frequent and / or long language breaks, can strongly distort this estimate. It's closed emphasize that an estimate of the reverberation time without use a measurement signal, for example during a telephone conversation, generally very problematic, since not It can easily be determined which signal components of the Microphone recorded sound signal direct sound and which Shares are echo or reverb. Under direct sound one understands the signal, which without a single reflection directly from the Speaker, so from the "sound source" reaches the microphone. A statistically based estimate of reverberation time can at most be done by having features more typical unvoiced, "clean" language with the characteristics of present, recorded, reverberated speech signal compared become.

In the second case, a measurement signal must be generated via an external sound source. for example, white noise, to be played, which known to the system. About the correlation between the played measuring signal and the signal, which over the Microphone of the communication device is received again then the reverberation time T60 is estimated. These Possibility is at most practicable for experimental setups, because, for example, the user of a phone is not expected can be, before or during each conversation only with the Phone to perform such a measurement.

The more accurate the reverberation time, the better allow the reverberation of an audio signal.

It is therefore an object of the invention to provide a method of operation a communication device and a communication device with To find means for interference suppression of audio signals, which compared to the previously known methods and hardware devices with a more accurate reverberation time also a better interference suppression of the audio signals.

These objects of the invention are achieved by the method the features of claim 1 and objectively by the communication device with the features of claim 8 solved. Advantageous developments of the invention are the subject of the subordinate claims.

The inventors have recognized that information contained in the Room impulse response are included, even for suppression of another Audio signals can be used. The room impulse response can be obtained by a known method. Advantageously, by the Acoustic Echo Cancelation method calculated room impulse response, using the AEC method in many phones already exists and which this room impulse response to suppress the resumed Audio signals also used to determine the reverberation time the environment can be used.

For example - in the case of two communication devices - That of a first communication device in handsfree mode radiated audio signal, usually the voice of the communication device user of the second communication device, inclusive the by the environment of the first communication device conditional noise components again from the microphone of the first Communications device recorded, it can be from these Audio signals with a first algorithm, first the room impulse response determine. The room impulse response implicitly the reverberation time T60, that is the reverberation time can be calculated from it.

Should now another audio signal, for example, the language the communication device user from the first communication device, which in turn are surrounded by the environment is annoying, so will be out of the first algorithm determined room impulse response the reverberation time of the Room determined. This reverberation time can then be used to the reverberation in the recorded speech signal of the first communication device user to determine. This is going on the inventors additionally took advantage of the knowledge that is the reverberation time also at different positions of the Sound source in the room does not change significantly.

According to this inventive concept, the inventors propose a method for operating a communication device, wherein the communication device audio signals to an environment radiates and on the one hand these audio signals including environmental superimposed interference components, at least Echo and reverberation included, resumes and on the other hand Audio signals from an external sound source, preferably one Communication device user, including their environment Noise, picking up, and a first algorithm a room impulse response of the environment determines to that effect improve that on the recorded audio signals of the external Sound source, preferably the communication user, a second suppression algorithm is applied, the used for suppression a reverberation time, which he from the determined by the first algorithm determined room impulse response.

This allows the reverberation time to suppress interference use of audio signals from an external sound source that off by radiation of a known audio signal and the subsequent recording of the reverberated in the room audio signal determined room impulse response can be calculated. Across from the estimate of the reverberation time of audio signals of an external Sound source, this method is more accurate.

The method is particularly suitable for communication devices, such as for radios, mobile devices or Festnetztelefone, because here is the possibility of radiation a known signal and the subsequent recording given is. But also for stand-alone devices, the audio signals via a loudspeaker and also audio signals can pick up via a microphone, the method is suitable due to the environmental condition of the stand-alone device to use the resulting reverberation time and to suppress interference.

In addition, the determination of the reverberation time is via this method much more possible, as compared to a previous one Estimation from the reverberant audio signal.

For example, the new procedure may be the basis for a Real-time parameterization and real-time adaptation of algorithms form the reverberation of speech signals.

It is advantageous if only the first algorithm the reverberation time is determined.

Alternatively, it is possible that only the second Suppressor algorithm determines the reverberation time.

Furthermore, it is advantageous if the reverberation time from the energetic Rejection of reverberation is calculated using the information about the speed of this waste in the Room impulse response is included. This can be a more accurate Determination of the reverberation time compared to the statistically based Estimation of the reverberation time done.

To determine the room impulse response, then the reverberation time can be determined in the new process in the first algorithm, an AEC algorithm (AEC = Acoustic Echo Cancelation). This AEC algorithm is available in many phones today and is actually to suppress the resumed audio signals used. The algorithm calculates a room impulse response, which according to the invention for determining the reverberation time can be used.

To suppress the recorded audio signals of the communication device user a second suppression algorithm is used. Such a second suppression algorithm should be under Utilization of the determined or accepted reverberation time due to the environment superimposed interference components, such as echo and reverb, from the recorded audio signal of the communication device user remove.

For the method, it is also advantageous if the Room impulse response as a function of frequency and preferably filtered through several band passes. This can the reverberation time, which is itself frequency dependent, depending on the frequency are determined.

At this point it should be mentioned that the application of the new Procedure very easily detected in two communication devices can be: The described method of operation of a communication device is based on the fact that the speaker of an audio system, for example radiating into a room and that the audio signal fading through the room is picked up again by the microphone of the audio system.

As proof, a voice connection between the two mobile subscribers built up. Then the first separates Mobile subscriber, while the second mobile subscriber speaks, the acoustic connection between speakers and Microphone, for example by covering the speaker with the hand. Noticed now the second mobile subscriber a significant deterioration of the quality of the audio signal, for Example in the form of a reverberated voice when the first mobile subscriber speaks, then the new procedure becomes Determining the reverberation time in the device of the first mobile radio subscriber applied. This assumes that a rewriting algorithm is applied. The interruption of the transmission path prevents the first mobile terminal an adaptation of the used "suppression algorithm" to the Reverberation time of the room.

For the objective solution of their task, the inventors propose also before, a known communication device with means for interference suppression of audio signals, wherein the communication device has at least one speaker, the audio signals radiates to an environment and continue at least one Microphone, with the one hand, these audio signals including environmental superimposed interference components, the at least echo and reverberation included, resumed and on the other hand audio signals from an external sound source, preferably a communication device user, including recorded their environmental interference components and a first means are provided in the communication device is that means for calculating a room impulse response the environment, to improve that a second means for the recorded audio signals of the external Sound source, preferably the communication user, including their environmental interference components is arranged, which is a means for determining the reverberation time having the reverberation time determined in the contained by the first means determined room impulse response is.

As a result, a communication device is provided, in which the reverberation time, by the utilization of the Radiation of a known audio signal and the subsequent Recording of the audio signal lost in the room via the determination the space impulse response has been determined, which is now also for filtering the audio signals of an external Sound source can be used. The suppression can here more accurate than before, because the reverberation time better and more accurately determined.

There is a possibility that only the first Means have program means and / or program modules, which determine the reverberation time.

Alternatively, however, only the second means can be used Have program means and / or program modules that the Determine reverberation time.

The first means may be via program means and / or program modules have an AEC algorithm (AEC = Acoustic Echo Cancellation) or an algorithm as in Welch, P.D. [1970], "The Use of Fast Fourier Transform for the Estimation of Power Spectra ", IEEE Trans Audio Electroacoustic, Vol AU15, pp70-73). The content of this References in the full text.

Furthermore, it is advantageous if the second means program means and / or program modules having an algorithm perform that by taking advantage of the environment certain reverberation time superimposed by the environment Noise components, such as echo and reverb, from the recorded audio signal of the communication device user.

The determination of the reverberation time as a function of the frequency and according to the frequency-dependent interference suppression of the audio signals is realized low in the communication device, if bandpass filters are arranged in the communication device, that filter the room impulse response.

The new communication device may be a telephone, for example in the form of a mobile station or a Wired telephone, a household electrical appliance or an electrical module of a vehicle with means for Voice input and voice acting.

In the following, the invention is based on preferred embodiments described with the aid of Figures 1 to 5, wherein in the figures the following abbreviations are used: 1: direct sound of a pulse-like audio signal; 2: echoes; 3: reverberation / reverberation curve; 4: Received signals from second communication device; 4.1: signals from the speech production module; 5: Algorithm for determining the reverberation time; 6: digital-to-analog converter; 7: speakers; 8.1: Signal, the directly from the loudspeaker to the microphone = direct sound; 8.2: Signal from the speaker that simply reflects on the object becomes = echo; 8.3: Signal from the speaker, several times and reflected diffusely on the object = reverberation; 9: object where the signals are reflected; 10: microphone; 11: Analog-to-digital converter; 12: Signals to be sent to the second Communication device; 12.1: signals to the speech recognition module; 13.1: first communication device; 13.2: second communication device; 13.3: interface for signaling; 13.4: Voice-controlled electrical appliance: 14: room impulse response; 15: Communication device user / operator; 15.1: signal that directly from the communication device user to the microphone = direct sound; 15.2: Signal of the communication device user, the simply reflected on the object = echo; 15.3: Signal of Communication device user, the multiple and diffuse on the object is reflected = reverberation; 16: algorithm for reverberation the signals 15.1 to 15.3; 17: interference suppression; 18: Speech synthesis module; 19: speech recognition module; A60: energy range, in which the energy drops by 60 decibels; T60: Reverberation time.

Figur 1:

Zeitliche Energieverteilung eines ursprünglich impulsförmigen Audiosignals in einem Raum;

Figur 2:

Zeitliche Energieverteilung desselben Audiosignals aus Figur 1, jedoch in einem kleineren Raum;

Figur 3:

Gemessene Raumimpulsantwort eines Raumes;

Figur 4:

Zwei Kommunikationsgeräte, die Signale austauschen, wobei in einem Kommunikationsgerät das neue Verfahren angewendet wird;

Figur 5:

Sprachgesteuertes Elektrogerät, in dem das neue Verfahren angewendet wird.

They show in detail:

FIG. 1:

Temporal energy distribution of an originally pulsed audio signal in a room;

FIG. 2:

Temporal energy distribution of the same audio signal of Figure 1, but in a smaller space;

FIG. 3:

Measured room impulse response of a room;

FIG. 4:

Two communication devices exchanging signals using the new method in a communication device;

FIG. 5:

Voice-controlled electrical appliance in which the new method is used.

FIG. 1 shows an example in a diagram of the temporal Energy distribution of an audio signal, which is in one Record space with a microphone and measure when a impulsive audio signal, for example a bang, occurs. This power distribution is obtained by entering the magnitude square forms a room impulse response and this logarithmiert.

On the ordinate of the diagram are the logarithmized signal amplitudes, as a measure of the energy of the audio signal, and on the abscissa the time, each in arbitrary units, applied.

One recognizes the so-called first line on the far left in the diagram Direct sound 1, which is directly from the Sound source passes to the measuring microphone. Then follow that in This example energetically weaker echoes 2, the once or twice reflected on walls of the room before they get to the measuring microphone.

Finally, followed by a triangle, the reverberation 3, which consists of quasi chaotic superimposed reflections of the Audio signal exists in the room and diffuse arrives at the measuring microphone.

The new method uses the reverberation time T60 of an audio signal, from the room impulse response 14, for a given Space is characteristic, was determined.

To determine the reverberation time T60 is shown in Figure 1 on the Ordinate of the diagram determines an energy range A60, the is in the range of the reverberation 3, in which the energy of the Reverberation drops by 60 decibels. The upper and the lower Limit value of the energy range A60 are first on the Reverberation curve 3 and then on the abscissa, ie the time axis projected. The projected area on the timeline corresponds the reverberation time T60.

At this point it should be mentioned that the energy sector is not necessarily be chosen with 60 decibels, but can also be chosen smaller or larger. For example can also be chosen an area in which the energy of the Reverberation drops by 30 decibels, for example. The value that obtained from the projection on the timeline must be appropriate by the factor of reduction / enlargement of the Energy, to be adjusted. At an energy range of only 30 decibels will be equal to the time period with the factor 2 multiplied to obtain the reverberation time T60.

In FIG. 2, in turn, the temporal energy distribution is exemplified a pulse-like audio signal, for example one Bang shown. In contrast to the boundary conditions, which were valid for the figure 1, the audio signal in a smaller space to be included. This manifests itself in one less reverberation 3. The reverberation curve 3 falls faster whereby the reverberation time T60 is lower than in FIG. 1 is. For the sake of simplicity, the direct sound was 1 and the Echoes 2 in the diagram of Figure 2 unchanged from the diagram taken over the figure 1. In a real measurement of a signal However, differences could occur here.

It can be seen that from the energetic waste of the reverberation 3, ie the negative slope of the reverberation curve 3, the reverberation time T60 can be determined.

FIG. 3 now shows a measured room impulse response 14 of a Space. On the ordinate are the signal amplitudes and the time is plotted on the abscissa. The speed of the waste of energy in the space impulse response Time is characteristic of this particular space. This speed is independent of the measurement signal and the Position of sound source and microphone in the room for that particular Room to be obtained.

FIG. 4 shows two communication devices 13.1 and 13.2, Replace the signals 4 and 12 via an interface 13.3. It may be in the communication devices 13.1 and 13.2, for example, to act on terminals in the mobile network. The interface 13.3 may be, for example around a transmitting / receiving antenna or an infrared interface act.

In the communication device 13.1, the new method is used.

The first communication device 13.1 should be in an environment located, for example, in a church, in the Hall effects occur. This environment is open by a one-sided Rectangle indicated by the reference numeral 9.

The signal 4 is via the interface 13.3 from the second Communication device 13.2 to the first communication device 13.1 sent and received by this. The signal 12 should be from first communication device 13.1 to the second communication device 13.2 be sent, it should be disrupted by the surroundings 9 of the first communication device 13.1 occur, be suppressed.

The first communication device 13.1 has at least one Digital-to-analog converter 6, which is the second communication device 13.2 sent digital signals 4 in analog Converts signals and forwards them to a loudspeaker 7. In addition, the first communication device 13.1 has a Microphone 10, which can record analog signals and over an analog-to-digital converter 11 digitized.

• Die Nachhallzeit, die für diese Umgebung 9 charakteristisch ist, ist in der Raumimpulsantwort enthalten. Die Raumimpulsantwort wiederum lässt sich aus dem Verhältnis der Signale 8.2 und 8.3 zum Signal 8.1 bestimmen.
• Die Nachhallzeit ändert sich an verschiedenen Positionen der Schallquelle im Raum nicht signifikant. Das heißt, die Signale 8.1 bis 8.3 die vom Lautsprecher 7 zum Mikrofon 10 gelangen und die Signale 15.1 bis 15.3, die vom Kommunikationsgerätenutzer 15 zum Mikrofon 10 gelangen, haben eine ähnliche Nachhallzeit.

The new method is intended to suppress the signal 15.1, as a rule speech signals, that a communication device user 15 sends to the microphone 10 of the first communication device 13.1. The interference suppression is done by suppressing the unwanted echo 15.2 and the unwanted Hall 15.3 as completely as possible. To be able to suppress this signal, the reverberation time T60 must be determined. Here, the new method makes use of:

• The reverberation time characteristic of this environment 9 is included in the spatial impulse response. The room impulse response in turn can be determined from the ratio of the signals 8.2 and 8.3 to the signal 8.1.
• The reverberation time does not change significantly at different positions of the sound source in the room. That is, the signals 8.1 to 8.3, which pass from the speaker 7 to the microphone 10, and the signals 15.1 to 15.3, which arrive from the communication device user 15 to the microphone 10, have a similar reverberation time.

In the new method, the already known reverberation time as follows for the suppression of the signal 15.1 available made. The sent from the second communication device 13.2 Signal 4 is converted by the digital-to-analog converter 6 and via the speaker 7 of the first communication device 13.1 issued. Analogous to the diagrams of FIGS. 1 and 2 the signal 4 in the form of direct sound 8.1, echo 8.2 and Reverberation 8.3 to the microphone 10 of the first communication device 13.1 arrive.

The direct sound becomes 8.1, the echo becomes 8.2 and the reverberation becomes 8.3 converted via an analog-to-digital converter 6 and over an algorithm 5, the room impulse response is determined.

Different methods can be used to determine the room impulse response be used.

Thus, a so-called AEC algorithm (AEC = Acoustic Echo Cancellation) are implemented. This algorithm will used in handsfree mode to echo the voice signal of the remote party, which radiated from the speaker 7 and unwanted by the microphone 10 resumed is going to compensate. This is done by estimating the Transmission path speaker 7 and microphone 10 an impulse response calculated. By folding the communication device 13.2 transmitted signal 4 with this impulse response and Subsequent subtraction of the thus calculated signal from Microphone signal takes place the echo suppression. The signal is suppressed by a Entstöreinheit 17.

Alternatively, to determine the room impulse response known algorithm which is first used by "Which" was published. This is how the Welch method describes (see also Welch, P.D. [1970], "The Use of Fast Fourier Transform for the Estimation of Power Spectra ", IEEE Trans Audio Electroacoustic, Vol AU15, pp70-73) determining a Impulse response by the emission of an output signal and the measurement of the input signal. Only requirement the output signal is the presence of sufficient energy in the frequency ranges to be considered.

If the room impulse response is determined with an algorithm 5, thus, the reverberation time can be determined from this. This reverberation time can also be used for filtering the signal 15.1 of the Communication device user 15, since the reverberation times, which is responsible for the transmission of signals 8.1 to 8.3 from the speaker 7 on the environment 9 to the microphone 10th and for the transmission of signals 15.1 to 15.3 from the communication device user 15 to the microphone 10, similar are. To this reverberation time from the room impulse response, the determined by the first algorithm 5 to determine Another algorithm 16 is provided to access the data of the algorithm 5 has, so on the room impulse response and the reverberation time contained therein. Then be the signals 15.1 to 15.3 with a Entstöreinheit 17th suppressed and output as signals 12.

FIG. 5 shows a special embodiment of a communication device. Here is the new procedure in a voice-driven Appliance 13.4 applied. This is the operator 15 of the voice-controlled electrical appliance only with the voice-controlled electrical appliance 13.4 in contact and not like in Figure 4 with another communication participant, the is located on a second communication device.

The voice-controlled electrical device 13.4 has a Voice generation module 18 to 4.1 signals, for example, the menu size of the electrical device 13.4, via the speaker 7 to spend. In addition, the voice-controlled electrical appliance has 13.4 via a speech recognition module 19 to signals 12.1, for example, recognize the language of the operator 15 to be able to.

Depending on the environment 9, those over the speaker 7 in the form of direct sound 8.1, echo 8.2 and reverberation 8.3 output signals unintentionally recorded by the microphone 10 become. To avoid this feedback is used in voice-controlled Electric device 13.4 an algorithm 5 is executed, the among other things, the room impulse response determined. Furthermore This feedback is suppressed with a Entstöreinheit 17.

To suppress the sent by the operator 15 to the microphone 10 Signal 15.1, algorithm 5 can not be used become. But the reverberation time, resulting from the room impulse response which determines in algorithm 5 which was almost the same for the signals 15.1 to 15.3 of the operator 15, can by another algorithm 16 used, with a Entstöreinheit 17 the signal 15.1 suppressed.

It is understood that the above features of Invention not only in the respectively specified combination, but also in other combinations or in isolation are usable without departing from the scope of the invention.

LIST OF REFERENCE NUMBERS

1

Direct sound of a pulse-like audio signal

2

Echos

3

Reverberation / reverberation curve

4

Received signals from the second communication device

4.1

Signals from the speech production module

5

algorithm

6

Digital to analog converter

7

speaker

8.1

Signal coming directly from the speaker to the microphone passes = direct sound

8.2

Signal of the speaker, which is simply reflected on the object = echo

8.3

Signal of the speaker, the multiple and diffuse reflected on the object = reverberation

9

Object on which the signals are reflected

10

microphone

11

Analog to digital converter

12

Signals to be transmitted to the second communication device

12.1

Signals to the speech recognition module

13.1

First communication device

13.2

Second communication device

13.3

Interface for signal transmission

13.4

Voice operated electrical appliance

14

Room impulse response

15

Communication device user / operator

15.1

Signal directly from the communication device user get to the microphone = direct sound

15.2

Signal of the communication device user, that simple is reflected on the object = echo

15.3

Signal of the communication device user, which is reflected several times and diffusely on the object = reverberation

16

Algorithm for rewriting the signals 15.1 to 15.3

17

descrambler

18

Speech synthesis module

19

Speech recognition module

A60

Energy range in which the energy is 60 decibels drops

T60

Reverberation time T60

Claims (18)

Method for operating a communication device (13.1, 13.2, 13.4), wherein
the communication device (13.1, 13.2, 13.4) emits audio signals (8.1 to 8.3) to an environment (9) and
on the one hand resumes these audio signals (8.1 to 8.3) including ambient superimposed interference components containing at least echo (8.2) and reverberation (8.3) and
on the other hand receives audio signals (15.1 to 15.3) of an external sound source, preferably of a communication device user (15), including their environmental interference components (15.2 and 15.3), and
the resumed audio signals (8.1 to 8.3) are used by a first algorithm (5) to determine a room impulse response of the environment,
characterized in that
on the recorded audio signals (15.1 to 15.3) of the external sound source, preferably of the communication device user (15), a second interference suppression algorithm (16) is used, which uses a reverberation time (T60), which it derives from the first algorithm (16). 5) determined room impulse response (14). Method according to the preceding claim 1,
characterized in that
only the first algorithm (5) determines the reverberation time (T60). Method according to the preceding claim 1,
characterized in that
only the second suppression algorithm (16) determines the reverberation time (T60). Method according to one of the preceding claims 1 to 3,
characterized in that
the reverberation time (T60) is calculated from the energetic fall of the reverberation (8.3) in the spatial impulse response (14). Method according to one of the preceding claims 1 to 4,
characterized in that
the first algorithm used is an AEC algorithm (5) (AEC = Acoustic Echo Cancellation). Method according to one of the preceding claims 1 to 5,
characterized in that
the second interference suppression algorithm (16), taking advantage of the reverberation time (T60) determined or assumed for the environment, removes the superimposed interference components (15.2 and 15.3) from the recorded audio signal (15.1 to 15.3) of the external sound source. Method according to one of the preceding claims 1 to 6,
characterized in that
to determine the reverberation time (T60) as a function of the frequency, the spatial impulse response (14) is filtered, preferably with bandpass filters. Communication device (13.1, 13.2, 13.4) with means for interference suppression of audio signals, wherein the communication device (13.1, 13.2, 13.4) via
at least one loudspeaker (7) which emits audio signals (8.1 to 8.3) to an environment (9) and
Furthermore, at least one microphone (10), with which on the one hand these audio signals (8.1 to 8.3) including environmental superimposed interference components containing at least echo (8.2) and reverberation (8.3) are resumed and
on the other hand, audio signals (15.1 to 15.3) of an external sound source, preferably of a communication device user (15), including their environmental interference components (15.2, 15.3) are recorded, and
in the communication device (13.1, 13.2, 13.4) a first means (5) is provided which has a means for calculating a room impulse response of the environment,
characterized in that
a second means (16) for the recorded audio signals (15.1 to 15.3) of the external sound source, preferably of the communication device user (15), including their environmental interference components (15.2, 15.3) is arranged, having a means for determining the reverberation time (T60), which determines the reverberation time (T60) contained in the space impulse response (14) determined by the first means (5). Communication device (13.1, 13.2, 13.4) according to the preceding claim 8,
characterized in that
exclusively the first means (5) has program means and / or program modules which determine the reverberation time (T60). Communication device (13.1, 13.2, 13.4) according to the preceding claim 8,
characterized in that
only the second means (16) has program means and / or program modules which determine the reverberation time (T60). Communication device (13.1, 13.2, 13.4) according to one of the preceding claims 8 to 10,
characterized in that
the program means and / or program modules of the first means include an AEC algorithm (5) (AEC = Acoustic Echo Cancelation). Communication device (13.1, 13.2, 13.4) according to one of the preceding claims 8 to 11,
characterized in that
the program means and / or program modules of the second means (16) include an algorithm which, utilizing the reverberation time determined by the environment, removes the superimposed interference components (15.2 and 15.3) from the recorded audio signal (15.1 to 15.3) of the external sound source (15). Communication device (13.1, 13.2, 13.4) according to one of the preceding claims 8 to 12,
characterized in that
Bandpass filters are provided which filter the spatial impulse response (14) and allow the determination of the reverberation time (T60) in dependence on the frequency. Communication device (13.1, 13.2, 13.4) according to one of the preceding claims 8 to 13,
characterized in that
the communication device (13.1, 13.2, 13.4) is a telephone. Communication device (13.1, 13.2, 13.4) according to the preceding claim 14,
characterized in that
the communication device (13.1, 13.2, 13.4) is a wired telephone. Communication device (13.1, 13.2, 13.4) according to one of the preceding claims 8 to 14,
characterized in that
the communication device (13.1, 13.2, 13.4) is a mobile radio terminal. Communication device (13.1, 13.2, 13.4) according to one of the preceding claims 8 to 13,
characterized in that
the communication device (13.1, 13.2, 13.4) is an electrical household appliance with means for voice input and voice output. Communication device (13.1, 13.2, 13.4) according to one of the preceding claims 8 to 17,
characterized in that
the communication device (13.1, 13.2, 13.4) is an electrical module of a vehicle having means for voice input and voice output.

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