METHOD FOR DYNAMIC SUPPRESSION OF SURROUNDING ACOUSTIC NOISE WHEN LISTENING TO ELECTRICAL INPUTS

• US 20110137649A1
• Filed: 12/02/2010
• Published: 06/09/2011
• Est. Priority Date: 12/03/2009
• Status: Active Grant

• Current Assignee: Oticon A/S (William Demant Fonden)
• Original Assignee: Oticon A/S (William Demant Fonden)
• Inventors: Thomsen, Anders Højsgaard, RASMUSSEN, Crilles Bak
• Granted Patent: US 9,307,332 B2
• Time in Patent Office: Days
• US Class Current: 704/231
• CPC Class Codes: H04R 2225/41 Detection or adaptation of hearing aid parameters or programs to listening situation, e.g. pub, forest
• CPC Class Codes: H04R 2225/43 Signal processing in hearing aids to enhance the speech intelligibility
• CPC Class Codes: H04R 2460/01 Hearing devices using active noise cancellation
• CPC Class Codes: H04R 25/356 Amplitude, e.g. amplitude shift or compression
• CPC Class Codes: H04R 25/43 Electronic input selection or mixing based on input signal analysis, e.g. mixing or selection between microphone and telecoil or between microphones with different directivity characteristics H04R25/407 takes precedence
• CPC Class Codes: H04R 25/554 using a wireless connection, e.g. between microphone and amplifier or using Tcoils

Abstract

A listening instrument includes a) a microphone unit for picking up an input sound from the current acoustic environment of the user and converting it to an electric microphone signal; b) a microphone gain unit for applying a specific microphone gain to the microphone signal and providing a modified microphone signal; c) a direct electric input signal representing an audio signal; d) a direct gain unit for applying a specific direct gain to the direct electric input signal and providing a modified direct electric input signal; e) a detector unit for classifying the current acoustic environment and providing one or more classification parameters; f) a control unit for controlling the specific microphone gain applied to the electric microphone signal and/or the specific direct gain applied to the direct electric input signal based on the one or more classification parameters.

Claims

1. A listening instrument adapted for being worn by a user and comprising,

a) a microphone unit for picking up an input sound from the current acoustic environment of the user and converting it to an electric microphone signal;

b) a microphone gain unit for applying a specific microphone gain to the electric microphone signal and providing a modified microphone signal;

c) a direct electric input signal representing an audio signal;

d) a direct gain unit for applying a specific direct gain to the direct electric input signal and providing a modified direct electric input signal;

e) a detector unit for classifying the current acoustic environment of the user and providing one or more classification parameters;

f) a control unit for controlling the specific microphone gain applied to the electric microphone signal and/or the specific direct gain applied to the direct electric input signal based on the one or more classification parameters;

wherein the detector unit comprises an own-voice detector (OVD) for determining whether or not the user is speaking at a given point in time.

2. A listening instrument according to claim 1 comprising a mixing unit for allowing a simultaneous presentation of the modified microphone signal and the modified direct electric input signal.

3. A listening instrument according to claim 1 wherein the detector unit comprises a level detector (LD) for determining the input level of the electric microphone signal.

4. A listening instrument according to claim 1 wherein the detector unit comprises a voice detector (VD) for determining whether or not the electric microphone signal comprises a voice signal.

5. A listening instrument according to claim 1 wherein the detector unit is adapted to classify the microphone signal as HIGH-NOISE or LOW-NOISE signal.

6. A listening instrument according to claim 1 adapted to estimate a NOISE input level during periods where the user'"'"'s own voice is NOT detected.

7. A listening instrument according to claim 6 adapted to use the NOISE input level to adjust the gain of the microphone and/or the electric input signal to maintain a constant signal to noise ratio.

8. A listening instrument according to claim 3 adapted to use the input level to adjust the gain of the microphone and/or the electric input signal in connection with a telephone conversation, when the direct electric input represents a telephone input signal.

9. A listening instrument according to claim 3 wherein the control unit is adapted to apply a relatively low microphone gain (G_A) and/or a relatively high direct gain (G_W) in case a current acoustic environment of the user is classified as a relatively HIGH-LEVEL or NOISE environment.

10. A listening instrument according to claim 1 wherein the control unit is adapted to apply a relatively high microphone gain (G_A) and/or a relatively high direct gain (G_W) in case a current acoustic environment of the user is classified as a relatively LOW-LEVEL or NO-NOISE environment.

11. A listening instrument according to claim 1 wherein the control unit is adapted to apply an intermediate microphone gain (G_A) and/or direct gain (G_W) in case a current acoustic environment of the user is classified as comprising VOICE.

12. Use of a listening instrument according to claim 1,

13. A method of operating a listening instrument adapted for being worn by a user, comprising

a) converting an input sound from the current acoustic environment of the user to an electric microphone signal;

b) applying a specific microphone gain to the electric microphone signal and providing a modified microphone signal;

c) providing a direct electric input signal representing an audio signal;

d) applying a specific direct gain to the direct electric input signal and providing a modified direct electric input signal;

e) classifying the current acoustic environment of the user, including determining whether or not the user is speaking at a given point in time, and providing one or more classification parameters;

f) controlling the specific microphone gain applied to the electric microphone signal and/or the specific direct gain applied to the direct electric input signal based on the one or more classification parameters;

g) determining whether or not the user is speaking at a given point in time.

14. A tangible computer-readable medium storing a computer program comprising program code means for causing a data processing system to perform at least some of the steps of the method of claim 13, such as steps b), d), e), f), g), when said computer program is executed on the data processing system.

15. A data processing system comprising a processor and program code means for causing the processor to perform at least some of the steps of the method of claim 13, such as steps b), d), e), f), g).

16. An audio processing device comprising

a) an electric input for receiving an electric microphone signal representing an acoustic signal;

b) a microphone gain unit for applying a specific microphone gain to the microphone signal and providing a modified microphone signal;

c) a direct electric input signal representing an audio signal;

d) a direct gain unit for applying a specific direct gain to the direct electric input signal and providing a modified direct electric input signal;

e) a detector unit for classifying the current acoustic environment of the user and providing one or more classification parameters;

f) a control unit for controlling the specific microphone gain applied to the electric microphone signal and/or the specific direct gain applied to the direct electric input signal based on the one or more classification parameters;

wherein the detector unit comprises an own-voice detector (OVD) for determining whether or not the user is speaking at a given point in time.