DVE system with normalized selection

• US 6,549,629 B2
• Filed: 02/21/2001
• Issued: 04/15/2003
• Est. Priority Date: 02/21/2001
• Status: Active Grant

• Current Assignee: Digisonix Incorporated
• Original Assignee: Digisonix Incorporated
• Inventors: Steenhagen, Shawn K., Finn, Brian M.
• Primary Examiner(s): Harvey, Minsun Oh
• Assistant Examiner(s): Grier, Laura A.
• Application Number:
  US09/790,408
• Publication Number:
  US 20020141601A1
• Time in Patent Office: 783 Days
• Field of Search: 381/80, 381/81, 381/94.5, 381/92, 381/122, 381/123, 381/110, 381/119, 379/202.01, 379/206.01, 379/406.01, 379/406.02, 379/406.03, 379/406.05, 379/406.04, 379/406.06, 379/406.07, 379/388.03, 379/388.04, 379/388.06, 379/388.05
• US Class Current: 381/92
• CPC Class Codes: H04R 3/005 for combining the signals of two or more microphones specially adapted for hearing aids H04R25/407

Abstract

In a DVE, digital voice enhancement, communication system, the selection decision for choosing which microphone to be active is based on a given function of the speech of a respective talker relative to his/her acoustic environment at the respective microphone. The selection decision is based on a selection technique normalizing at least one of a) different microphone sensitivities and b) different background noise levels at the respective microphones, preferably based on the ratio of how much louder a talker speaks over the background noise at his/her respective microphone.

Claims

1. A digital voice enhancement communication system comprising:

a plurality of microphones;

at least one loudspeaker;

a switch for selecting which microphone to electrically couple to said at least one loudspeaker so that a listener at said at least one loudspeaker can hear the speech of a talker at the selected microphone, the selection decision being based on a given function of the speech of a respective talker relative to his/her acoustic environment at the respective microphone, wherein said selection decision is based on the ratio $S<br><br>\text{\hspace{1em}<br><br>}<br><br>N<br><br>\text{\hspace{1em}<br><br>}<br><br>N<br><br>\text{\hspace{1em}<br><br>}<br><br>R=\frac{f<br><br>\left(\mathrm{voice}+\mathrm{noise}\right)}{f<br><br>\left(\mathrm{noise}\right)}$

where SNNR is the ratio of speech plus noise to noise, and f is a given function thereof.

2. The invention according to claim 1 wherein f is magnitude.

3. The invention according to claim 2 wherein f is average magnitude.

4. The invention according to claim 3 wherein f is power.

5. The invention according to claim 4 wherein f is average power.

6. The invention according to claim 1 wherein f is peak hold.

7. The invention according to claim 6 wherein f is peak hold with a given decay rate.

8. The invention according to claim 1 wherein said selection decision is based on the ratio of how much louder a talker speaks over the background noise at his/her respective microphone.

9. A selection method for a digital voice enhancement communication system having a plurality of microphones, and at least one loudspeaker, comprising selecting which microphone to electrically couple to said at least one loudspeaker so that a listener at said at least one loudspeaker can hear the speech of a talker at the selected microphone, basing the selection decision on a given function of the speech of a respective talker relative to his/her acoustic environment at the respective microphone,

and comprising basing the selection decision on the ratio $S$

 



N

 



N

 



R=f

(voice+noise)f

(noise)

where SNNR is the ratio of speech plus noise to noise, and f is a given function thereof.

10. The method according to claim 9 wherein f is magnitude.

11. The method according to claim 10 wherein f is average magnitude.

12. The method according to claim 9 wherein f is power.

13. The method according to claim 12 wherein f is average power.

14. The method according to claim 9 wherein f is peak hold.

15. The method according to claim 14 wherein f is peak hold with a given decay rate.

16. The method according to claim 9 comprising basing said selection decision on the ratio of how much louder a talker speaks over the background noise at his/her respective microphone.