DEVICE, SYSTEM AND PROCESS FOR AUDIO SIGNAL PROCESSING

Abstract

An audio processing device (100) includes a correction microphone (110), a reference microphone (120), a classification unit (130), an active noise cancellation (ANC) unit (140), and a speaker (150). The correction microphone is arranged in an area adjacent to an ear of a user of the device and picks up acoustic signals in the area and outputs same as a correction signal. The reference microphone picks up surrounding noises (124) from a surrounding area of the user and outputs same as a reference signal. The classification unit receives the reference signal and splits the reference signal corresponding to a spectrum and amplitude thereof into signal components of two or more classes and outputs a classified signal. The ANC unit receives and processes the correction signal based on the classified signal and outputs a corresponding audio signal. The speaker receives the audio signal and provides a corresponding acoustic signal output.

Claims

1. A device for noise-dependent audio signal processing, the device comprising: a correction microphone arranged in an immediate vicinity of an area intended for an ear of a user of the device, the correction microphone being configured to pick up acoustic signals in the area intended for the ear and to output a correction signal corresponding to the picked up acoustic signals; a reference microphone arranged and configured to pick up surrounding noises from a surrounding area of the user of the device and to output a reference signal corresponding to the pick up surrounding noises; a classification unit configured to receive the reference signal and to split the reference signal corresponding to a reference signal spectrum of the reference signal and a reference signal amplitude of the reference signal into signal components of the reference signal of more than two classes and to output a classified signal based on the signal components of the reference signal of more than two classes, wherein the classes comprise at least one of the following groups of signals and/or noises: siren signals, vehicle noises, voice signals, pump noises, ventilation noises, fire noises; an active noise cancellation unit configured to receive the correction signal to process the correction signal based on the classified signal and to output a corresponding audio signal; and a speaker configured to receive the audio signal and to provide a corresponding acoustic signal output.

2. A device in accordance with claim 1, further comprising a signal amplifier configured to amplify the correction signal, or the reference signal or the audio signal or any combination of the correction signal, the reference signal and the audio signal.

3. A device in accordance with claim 1, wherein the active noise cancellation unit is configured to determine the audio signal based on the classified signal such that the acoustic signal output based on the audio signal is suitable to interfere destructively with components of the surrounding noises which correspond to signal components of the reference signal from at least one class.

4. A device in accordance with claim 1, wherein the active noise cancellation unit is configured to assign a corresponding group of signals and/or noises to the classes of the classified signal and to process the correction signal based on the signal component of the classified signal, which signal component is assigned to at least one predefined group of signals and/or noises, such that the acoustic signal output based on the audio signal is suitable to interfere with components of the surrounding noises, which correspond to signal components of the reference signal from the at least one predefined group of signals and/or noises such that surrounding noises of this at least one predefined group of signals and/or noises are perceptible with a predefined amplitude in the area intended for the ear of the user of the device.

5. A device in accordance with claim 1, further comprising: an additional speaker; and an additional correction microphone, wherein: the additional speaker is configured to receive the audio signal or an additional audio signal output the active noise cancellation unit and to provide a corresponding, additional, acoustic signal output; the additional correction microphone is arranged in an immediate vicinity of an area intended for another ear of the user of the device and is configured to pick up acoustic signals in an area intended for the other ear and to output an additional correction signal based on the picked up acoustic signals; and the active noise cancellation unit is further configured to receive the additional correction signal and to process the correction signal and the additional correction signal based on the classified signal.

6. A device in accordance with claim 1, further comprising at least one additional reference microphone, which is arranged and configured to pick up surrounding noises from a surrounding area of the user of the device and to output them as an additional reference signal based on the pick up surrounding noises, wherein the classification unit is configured to output the classified signal based on the reference signal and on the additional reference signal.

7. A device in accordance with claim 1, further comprising, a microphone holder connecting the correction microphone and the speaker to fix a relative position of the correction microphone and the first speaker in relation to one another.

8. A system for noise-dependent audio signal processing, the system comprising: a gas mask or a helmet or a helmet and gas mask, the gas mask or the helmet or the helmet and gas mask having an area intended for an ear of a user of the gas mask; and a device for noise-dependent audio signal processing, the device comprising: a correction microphone arranged in an immediate vicinity of the area intended for an ear of a user of the device, the correction microphone being configured to pick up acoustic signals in the area intended for the ear and to output a correction signal corresponding to the picked up acoustic signals; a reference microphone arranged and configured to pick up surrounding noises from a surrounding area of the gas mask or the helmet or the helmet and gas mask and to output a reference signal corresponding to the pick up surrounding noises; a classification unit configured to receive the reference signal and to split the reference signal corresponding to a reference signal spectrum of the reference signal and a reference signal amplitude of the reference signal into signal components of at least one first class and at least one second class and to output a classified signal; an active noise cancellation unit configured to receive the correction signal to process the correction signal based on the classified signal and to output a corresponding audio signal; a speaker configured to receive the audio signal and to provide a corresponding acoustic signal output in the area intended for an ear of a user of the gas mask, wherein the classification unit is configured to output the reference signal in signal components of more than two classes; and the classes comprise at least one of the following groups of signals and/or noises: Siren signals, vehicle noises, voice signals, pump noises, ventilation noises, fire noises

9. A system in accordance with claim 8, wherein the reference microphone is arranged on an outer surface of the gas mask or of the helmet or the helmet and gas mask, which outer surface points away from a user of the gas mask or the helmet or the helmet and gas mask.

10. A process for noise-dependent audio signal processing, the process comprising the steps of: picking up of acoustic signals in an area intended for an ear of a user of this process and forwarding a corresponding correction signal; picking up of noises surrounding a user and forwarding a corresponding reference signal; receiving the reference signal and splitting the reference signal corresponding to a reference signal spectrum and a reference signal amplitude into signal components of at least one first class and at least one second class and outputting of a corresponding classified signal; receiving the correction signal and processing the correction signal, based on the classified signal, by a provided active noise cancellation unit and outputting a corresponding audio signal from the provided active noise cancellation unit; and receiving of the audio signal and providing a corresponding acoustic signal output.

11. A process in accordance with claim 10, further comprising the step of: amplifying the correction signal, or amplifying the reference signal; or amplifying the audio signal; or amplifying one or more of the correction signal and the reference signal and the audio signal.

12. A process in accordance with claim 10, further comprising the steps of assigning a predefined group of signals and/or noises to a corresponding class of the classified signal; processing the correction signal based on the signal component of the classified signal, which signal component is assigned to at least one predefined group of signals and/or noises, by the Active noise cancellation unit such that the acoustic signal output based on the audio signal is suitable to interfere with components of the surrounding noises, which correspond to signal components of the reference signal from the at least one predefined group of signals and/or noises such that surrounding noises of the at least one predefined group of signals and/or noises are perceptible with a predefined amplitude in the area that is intended for the ear of the user of this process.

13. A process in accordance with claim 10, further comprising the steps of: picking up of other acoustic signals in an area intended for another ear of the user and forwarding a corresponding additional correction signal; receiving the additional correction signal and processing of the correction signal and of the additional correction signal based on the classified signal; and receiving the audio signal and providing an additional acoustic signal output in the area intended for the other ear of the user of this process.

14. A process in accordance with claim 10, the process further comprising the steps of: picking up of other noises surrounding a user and forwarding a corresponding additional reference signal; and outputting the classified signal based on the reference signal and based on the additional reference signal.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0063] In the drawings:

[0064] FIG. 1 is a schematic view of a configuration of a device according to a first exemplary embodiment of the first aspect of the present invention;

[0065] FIG. 2 is a schematic view of a configuration of a device according to a second exemplary embodiment of the first aspect of the present invention;

[0066] FIG. 3 is a schematic view of a configuration of a device according to a third exemplary embodiment of the first aspect of the present invention;

[0067] FIG. 4 is a perspective view of a system according to a first exemplary embodiment of the second aspect of the present invention;

[0068] FIG. 5 is a perspective view of a system according to a second exemplary embodiment of the second aspect of the present invention;

[0069] FIG. 6 is a perspective view of a system according to a third exemplary embodiment of the second aspect of the present invention;

[0070] FIG. 7 is a perspective view of a system according to a fourth exemplary embodiment of the second aspect of the present invention; and

[0071] FIG. 8 is a block diagram of a process according to an exemplary embodiment of the third aspect of the present invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0072] Referring to the drawings, FIG. 1 shows a schematic configuration of a device 100 according to a first exemplary embodiment of the first aspect of the present invention.

[0073] The device 100 for noise-dependent audio signal processing comprises a correction microphone 110, a reference microphone 120, a classification unit 130, an ANC unit 140 and a first speaker 150.

[0074] The correction microphone 110 is arranged in an immediate vicinity of an area 114 intended for an ear of a user of the device. The correction microphone 110 is configured to pick up acoustic signals in the area 114 intended for the ear and to forward (output) them as a correction signal 118. The correction microphone 110 is oriented in this case towards the area 114 intended for the ear.

[0075] The reference microphone 120 is arranged and configured to pick up surrounding noises 124 from a surrounding area of the user of the device 100 and to forward (output) them as a reference signal 128. The reference microphone 120 is oriented in this case towards the surrounding area of the user of the device 100. The directions, in which the correction microphone 110 and the reference microphone 120 are each oriented, preferably differ here.

[0076] The classification unit 130 is configured to receive the reference signal 128 and to split the reference signal 128 corresponding to a reference signal spectrum and a reference signal amplitude into signal components of at least one first class and at least one second class and to output a classified signal 134. In this embodiment, the splitting into the first and second class is based on a signal processing of the reference signal 128 by a support vector machine applied to the spectrum and amplitude of the reference signal 128. As an alternative or in addition, in another exemplary embodiment, not shown, another prior-art pattern recognition process is used, for example, based on neural networks and/or on a code book.

[0077] The ANC unit 140 is configured to receive the correction signal 118, to process it based on the classified signal 134 and to output it as an audio signal 144.

[0078] The first speaker 150 is configured to receive the audio signal 144 and to provide a corresponding acoustic signal output 154. In the present exemplary embodiment, the first speaker 150 is arranged in the immediate vicinity of the area 114 intended for the ear. Furthermore, the first speaker 150 is oriented towards this area 114. In the present embodiment, the correction microphone 110 and the first speaker 150 are arranged at a distance from one another, namely in different edge areas of the area 114 intended for the ear. As a result, the correction microphone 110 is prevented from only picking up the acoustic signal output 154 of the first speaker 150 as acoustic signals and forwarding (outputting) them as a correction signal 118. Thus, it is made possible for the correction microphone 110 to also pick up surrounding noises 14 in addition to the acoustic signal output 154 as acoustic signals and to forward (output) them as a correction signal 118. The correction microphone 110 and the first speaker 150 are arranged adjacent to one another in another alternative exemplary embodiment.

[0079] An active noise reduction, used as active noise suppression in the present embodiment, which is made possible by the ANC unit 140, is achieved in this exemplary embodiment by the ANC unit 140 being configured to determine the audio signal 144 based on the classified signal 134 such that the acoustic signal output 154 corresponding to the audio signal 144 interferes destructively at least with components of the surrounding noises 124. The components of the surrounding noises 124, with which the acoustic signal output 154 interferes destructively and differs, correspond here to the signal components of the reference signal 128 from at least one class.

[0080] The device 100 according to the exemplary embodiment being shown is configured such that the classification unit 130 and the ANC unit 140 are configured as electronic components which are separated from one another. The classification unit and the ANC unit are configured as components of a single signal processing unit of the device in an alternative exemplary embodiment according to the present invention, not shown.

[0081] FIG. 2 shows a schematic configuration of a device 200 according to a second exemplary embodiment of the first aspect of the present invention.

[0082] The device 200 differs from the device 100 shown in FIG. 1 by the features described below.

[0083] The ANC unit 240 of the device 200 is further configured to receive the reference signal 128 and the correction signal 218 and to process them based on the classified signal 234. As a result, many pieces of signal information, especially related to the surrounding noises 124, can advantageously especially be taken into consideration during the processing by the ANC unit 240. The classified signal 234 in this exemplary embodiment is a signal synchronized in real time with the reference signal 128, which indicates the class currently assigned to the signal component of the reference signal 128. As a result, the classified signal 234 in this exemplary embodiment is a pure control variable for the ANC unit 240.

[0084] By contrast to the correction signal 118 from FIG. 1, the correction signal 218 is generated by processing using the signal of the correction microphone 110 and subsequent frequency band correction by a filter unit 260. The correction signal 218 is hence a processed correction signal 218.

[0085] Furthermore, the device 200 additionally comprises a signal amplifier 265, which is configured to amplify a provided audio signal 244, before it is received by the first speaker 150.

[0086] In an exemplary embodiment, not shown, an alternative or additional signal amplifier is configured to amplify the reference signal and/or the correction signal.

[0087] In another exemplary embodiment, not shown, the filter unit is configured to function as a high-pass filter and/or as a low-pass filter. As a result, spectral components that are irrelevant for the acoustic output can be filtered out already before an unnecessary further processing.

[0088] The classification unit 230 of the device 200 is further configured to output the reference signal 128 in signal components of more than two classes. In this case, the classification unit 230 is configured to take into consideration classes of the following groups of signals and/or noises: Siren signals, vehicle noises, voice signals, pump noises, ventilation noises, and fire noises. In other exemplary embodiments, the classes comprise at least one of the specified groups of signals and/or noises. Based on a classification carried out by the classification unit 230 in this manner, the ANC unit 240 is configured to provide the audio signal 244 such that the acoustic signal output 154 by the first speaker 150 interferes with the acoustic signals in the area intended for the ear such that surrounding noises of a particular predefined group of signals and/or noises are perceptible with a corresponding predefined amplitude in the area intended for the ear of the user of the device 200. As a result, it is achieved in the present embodiment that speech can be perceived in a volume that makes possible a communication with bystanders. Furthermore, typical disturbing noises, such as pump noises, ventilation noises and fire noises are extensively suppressed, while siren signals and vehicle noises are kept at a medium volume, in order to keep the exposure to noise of the user of the device 200 within a framework that is not harmful to health.

[0089] FIG. 3 shows a schematic configuration of a device 300 according to a third exemplary embodiment of the first aspect of the present invention.

[0090] The device 300 according to the present invention differs from the devices 100 and 200 by the features described below.

[0091] The device 300 comprises, in addition to the reference microphone 320, two additional reference microphones 322, 324. These three reference microphones are oriented in three different directions in relation to the user of the device 300. Furthermore, the reference microphones are configured to pick up and to forward (output) surrounding noises from the surrounding area of the user of the device. In this case, the reference microphone 320 forwards (outputs) the reference signal 328 and the additional reference microphones 322, 324 forward (output) a respective additional reference signal 329, 329. The classification unit 330 according to the present invention is configured here to output the classified signal 334 based on the reference signal 328 and on the two additional reference signals 329, 329.

[0092] Moreover, the device 300 comprises a second speaker 370 and an additional correction microphone 380. The second speaker 370 is configured to receive an additional audio signal 346 outputted by the ANC unit 340 and to provide a corresponding, additional, acoustic signal output 374. In an exemplary embodiment, not shown, the additional audio signal corresponds to the audio signal. The additional correction microphone 380 is arranged in an immediate vicinity of an area 314 intended for another ear of the user of the device 300 and is configured to pick up acoustic signals in the area 314 intended for the other ear and to forward (output) them as an additional correction signal 384.

[0093] The ANC unit 340 is configured here to receive the additional correction signal 384 and to process the correction signal 118 and the additional correction signal 384 based on the classified signal 334. As a result of this processing, the audio signal 144 and the additional audio signal 346 are outputted. The audio signal 144 and the additional audio signal 346 are configured here such that the active noise suppression in the respective area 114, 314 intended for an ear of the user of the device 300 is dependent on the position of this respective area in relation to a noise direction of a signal or noise belonging to a suppressed class. In this connection, the noise direction is determined by a known orientation of the three reference microphones 320, 322, 324. In an exemplary embodiment, not shown, the same audio signal is sent to the speakers 150 and 380.

[0094] FIG. 4 shows a perspective view of a system 400 according to a first exemplary embodiment of the second aspect of the present invention.

[0095] The system 400 according to the present invention comprises the device 100 shown in FIG. 1, with the only difference being that the classification unit and the ANC unit are embodied in a common signal processing unit 410. The manner of functioning of all the components takes place as described within the framework of FIG. 1.

[0096] Furthermore, the system 400 according to the present invention comprises a helmet 420, wherein the first speaker 150 is arranged such that the acoustic signal output takes place in the area intended for the ear (configured for receiving the ear) of a user of the helmet 420. Furthermore, the correction microphone 110 is arranged in the immediate vicinity of the area intended for the ear. In this case, the correction microphone 110 is fastened to the first speaker 150 via a microphone holder 425, as a result of which a predefined relative position of the correction microphone 110 and the first speaker 150 can also be maintained in case of a movement of the system 400 or under the effect of a physical stress.

[0097] In the exemplary embodiment shown, the correction microphone 110 and the first speaker 150 are arranged in the fabric of a strap 430 of the helmet 420.

[0098] The reference microphone 120 is arranged on an outer side of the helmet 420. In this case, the reference microphone 120 is oriented towards a direction pointing away from the user of the system 400. As a result, it is advantageously ensured that the surrounding noises 124 picked up by the reference microphone 120 are not formed by the acoustic signal output from the first speaker 150 to a significant extent.

[0099] In order to ensure protection against noise, a user of the system 400 would use a prior-art passive hearing protector in the ear that is not located at the correction microphone 110.

[0100] In one exemplary embodiment, not shown, the first speaker of the system is not arranged in an immediate vicinity of the area intended for the ear but rather in another area of the helmet, wherein the acoustic signal output is sent via a resonance space to the user of the system, especially to at least one ear of the user of the system.

[0101] FIG. 5 shows a perspective view of a system 500 according to a second exemplary embodiment of the second aspect of the present invention.

[0102] By contrast to the system 400 shown in FIG. 4, the system 500 comprises the device 300 shown in FIG. 3.

[0103] The classification unit and the ANC unit are arranged here in a housing, not shown, in an area of the helmet, which area is located on the rear inside from the viewpoint of the user.

[0104] The reference microphones 320, 322, 324 are arranged in different positions on an outer side of the helmet 420 such that they are oriented in different directions. As a result, surrounding noises can be especially easily picked up from different directions.

[0105] In one exemplary embodiment of the system according to the present invention, which is not shown, a plurality of reference microphones are arranged on a helmet strap, which can be arranged on a lower edge of a helmet, especially of a half-shell helmet. As a result, the system according to the present invention can advantageously be arranged on existing helmets in an especially simple manner.

[0106] FIG. 6 shows a perspective view of a system 600 according to a third exemplary embodiment of the second aspect of the present invention.

[0107] The system 600 according to the present invention has the device shown in FIG. 3, as well as a gas mask 610, wherein the first speaker 150 and the second speaker 370 are arranged on a mask body 615 or on a strap 618 of the gas mask 610 such that the acoustic signal output and the additional acoustic signal output take place each in an area intended for the ear of the user of the gas mask. The correction microphone 110 and the additional correction microphone 380 are each arranged in the immediate vicinity to this area. In this case, the correction microphone 110 and the additional correction microphone 380 are arranged at a respective housing of the first speaker and of the second speaker 150, 370, taking the directional characteristic of the microphones 110, 380 into consideration. The two microphones 110, 380 are advantageously omnidirectional microphones in the exemplary embodiment shown. Microphones with different directional characteristics are used in exemplary embodiments, not shown.

[0108] The three reference microphones 320, 322, 324 are integrated in a connection piece 620 of the gas mask 610 for the connection of a gas filter or of a compressed air breathing apparatus.

[0109] Within a gas mask, the device according to the present invention can especially advantageously be integrated into existing electronic devices of prior-art communication systems for gas masks.

[0110] FIG. 7 shows a perspective view of a system 700 according to a fourth exemplary embodiment of the second aspect of the present invention.

[0111] The system 700 according to the present invention comprises a gas mask 710, similar to the system 600 shown in FIG. 6. A device according to the present invention integrated in it comprises two reference microphones 720, 724, which are arranged on an outer side of the gas mask 720 pointing in different directions. The correction microphone 730 and the additional correction microphone 734 are integrated together with the first speaker and the second speaker 740, 744 in a respective separate ear part 750, 754, which is each fastened to the gas mask 710. The correction microphone 730 and the additional correction microphone 734 are in this case oriented towards the respective speaker 740, 744.

[0112] The system 700 according to the present invention especially advantageously makes it possible to individually adapt the position of the correction microphone and the speaker to a present individual head shape of the user of the gas mask due to the movable separate ear parts 750, 754.

[0113] FIG. 8 shows a block diagram of a process 800 according to an exemplary embodiment of the third aspect of the present invention.

[0114] The process 800 according to the present invention for noise-dependent audio signal processing has in this case the following steps in chronological order.

[0115] A first step 810 comprises the picking up of acoustic signals in an area intended for an ear of a user of this process and the forwarding (outputting) of a corresponding correction signal.

[0116] A next step 820 comprises the picking up of noises surrounding a user of this process and the forwarding (outputting) of a corresponding reference signal.

[0117] A next step 830 comprises the receiving of the reference signal, the splitting of the reference signal corresponding to its spectrum and its amplitude into signal components of at least one first class and at least one second class and the outputting of a corresponding classified signal.

[0118] A next step 840 comprises the receiving of the correction signal, the processing of the correction signal based on the classified signal by a provided ANC unit and the outputting of a corresponding audio signal.

[0119] A last step 850 comprises the receiving of the audio signal and the provision of a corresponding acoustic signal output.

[0120] The process 800 according to the present invention is repeated in fast chronological order, wherein the steps can be carried out at the same time or almost at the same time. Thus, the active noise suppression by the provided ANC unit is based on the fact that the acoustic signal output is constantly adapted to a current surrounding noise in order to ensure thereby the desired partially destructive interference between the acoustic signal output and the current surrounding noises.

[0121] While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.

LIST OF REFERENCE NUMBERS

[0122] 100, 200, 300 Device according to the present invention [0123] 110, 730 Correction microphone [0124] 114, 314 Area intended for the ear of a user [0125] 118 Correction signal [0126] 120, 320, 720 Reference microphone [0127] 124 Surrounding noises [0128] 128, 328 Reference signal [0129] 130, 230, 330 Classification unit [0130] 134, 234 Classified signal [0131] 140, 240, 340 ANC unit [0132] 144, 244 Audio signal [0133] 150, 740 First speaker [0134] 154 Acoustic signal output [0135] 218 Processed correction signal [0136] 260 Filter unit [0137] 265 Signal amplifier [0138] 322, 324, 724 Additional reference microphone [0139] 329, 329 Additional reference signal [0140] 346 Additional audio signal [0141] 370, 744 Second speaker [0142] 374 Additional acoustic signal output [0143] 380, 734 Additional correction microphone [0144] 384 Additional correction signal [0145] 400, 500, 600, 700 System according to the present invention [0146] 410 Common signal processing unit [0147] 420 Helmet [0148] 425 Microphone holder [0149] 430 Strap of the helmet [0150] 610, 710 Gas mask [0151] 615 Mask body [0152] 618 Strap of the gas mask [0153] 620 Connection piece [0154] 750 First ear part [0155] 754 Second ear part [0156] 800 Process according to the present invention [0157] 810, 820, 830, 840, 850 Process steps