Microphone position and speech level sensor

• US 6,941,161 B1
• Filed: 09/13/2001
• Issued: 09/06/2005
• Est. Priority Date: 09/13/2001
• Status: Expired due to Term

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Plantronics, Inc. (HP Inc.)
• Inventors: Bobisuthi, James F., Burson, Steven F., Gollbach, Lawrence W., Bernardi, Robert J., Woo, Allen
• Primary Examiner(s): Tran, CongVan
• Application Number:
  US09/952,434
• Time in Patent Office: 1,454 Days
• Field of Search: 455/569.1, 455/556.1, 455/557, 381/71.1, 381/56, 381/58, 381/72, 381/73.1, 379/142.13, 379/167.13, 379/406.08, 379/428.02
• US Class Current: 455/569.1
• CPC Class Codes: H04M 1/6008 in the transmitter circuit
• CPC Class Codes: H04M 1/6033 for providing handsfree use or a loudspeaker mode in telephone sets arrangements for preventing acoustic echo H04M9/08
• CPC Class Codes: H04M 1/6058 involving the use of a headset accessory device connected to the portable telephone

Abstract

Improper microphone position and speech level on a telephone headset is sensed by comparison of a speech envelope to multiple signal threshold levels. A first threshold is used to determine whether a headset user is talking. A second threshold is used to determine whether a signal level at the microphone is sufficiently strong for proper communication. An indicator is activated when the user is talking and the signal level is too weak. Typically, a weak signal is caused by a mispositioned microphone or a user talking too softly.

Claims

1. A telephone headset adapter, comprising:

a headset interface adapted to couple a headset to a telephone, and to receive a speech signal from a microphone on the headset; and

a speech level sensing circuit coupled to the headset interface to receive the speech signal from the headset interface, and adapted to determine whether a speech level at the microphone is at an improper level, and provide an output signal in response to the occurrence of an improper speech level.

2. The telephone headset adapter of claim 1 further comprising a visual indicator coupled to the speech level sensing circuit, the visual indicator adapted to visually indicate an improper speech level at the microphone.

3. The telephone headset adapter of claim 2 wherein the visual indicator is a light emitting diode positioned on the headset adapter.

4. The telephone headset adapter of claim 2 wherein the visual indicator is a light emitting diode positioned on the headset.

5. The telephone headset adapter of claim 2 wherein the visual indicator is a light emitting diode that is a plug-in accessory for the headset adapter.

6. The telephone headset adapter of claim 1 further comprising a tone generator coupled to the speech level sensing circuit, the tone generator adapted to generate a tone in response to an improper speech level at the microphone.

7. The telephone headset adapter of claim 1 wherein the output signal is provided without providing a feedback signal of the input signal to a speaker on the headset.

8. The telephone headset adapter of claim 1 wherein the speech level sensing circuit detects an improper speech level by comparing the speech signal level at the microphone to a noise threshold and an audible threshold.

9. The telephone headset adapter of claim 8 wherein the noise threshold is dynamically set.

10. The telephone headset adapter of claim 9 wherein the noise threshold is set using an ambient noise level on a signal from the telephone headset during a period of time that a user is not talking.

11. The telephone headset adapter of claim 8 wherein the speech level sensing circuit further comprises:

a first comparator adapted to determine whether the speech signal level is above a noise threshold;

a second comparator adapted to determine whether the speech signal level is below an audible threshold; and

an indicator coupled to the first and second comparators, the indicator adapted to indicate that a speech signal is at an improper level in response to the speech signal level being above the noise threshold and below the audible threshold.

12. The telephone headset adapter of claim 11 further comprising indicator control logic having a first input coupled to the first comparator, a second input coupled to the second comparator, and an output coupled to the indicator, the indicator control logic adapted to activate the indicator for a minimum time period in response to an improper speech level.

13. The telephone headset adapter of claim 11 further comprising first logic device having an input coupled to the first comparator and an output coupled to the indicator, the first logic device adapted to provide a period of time to permit a speech peak to develop before enabling the indicator.

14. The telephone headset adapter of claim 11 further comprising a second logic device having an input coupled to the second comparator and an output coupled to the indicator, that monitors speech peaks within a speech signal to determine whether a speech signal level is above the audible threshold.

15. The telephone headset adapter of claim 14 wherein the detection of a speech peak, within the speech signal, that is above the audible threshold inhibits an improper speech level indication for a period of time following the detection of the speech peak.

16. A method for detecting an improper speech signal level at a microphone, the method comprising:

receiving a speech signal from the microphone;

determining whether a microphone user is talking by comparing the speech signal level to a noise threshold;

determining whether the speech signal level is improper by comparing the speech signal level to an audible level; and

activating an indicator when the speech signal level is between the noise threshold and the audible threshold.

17. The method of claim 16 wherein the microphone is part of a telephone headset.

18. The method of claim 16 wherein an improper speech level is visually indicated to a user.

19. The method of claim 18 wherein a light emitting diode positioned on a headset adapter is used to visually indicate an improper speech signal level.

20. The method of claim 18 wherein a light emitting diode positioned on the headset is used to visually indicate an improper speech signal level.

21. The method of claim 18 wherein a light emitting diode that is a plug-in accessory for a headset adapter is used to visually indicate an improper speech signal level.

22. The method of claim 16 wherein an improper speech signal level is audibly indicated to a user.

23. The method of claim 16 wherein an improper speech level indication is provided without providing a feedback signal to a speaker on the headset.

24. The method of claim 16 further comprising the step of delaying an improper speech signal indication for a period of time to allow a speech envelope to develop.

25. The method of claim 23 further comprising the step of providing a minimum period of time in which the indicator remains activated after detecting an improper speech level.

26. The method of claim 16 wherein speech peaks within the speech signal are monitored to determine whether the speech signal level is below the audible threshold.

27. The method of claim 26 wherein detection of a speech peak, within the speech signal, that is above the audible threshold inhibits an improper speech level indication for a period of time following the detection of the speech peak.

28. The method of claim 16 wherein the noise threshold is dynamically set.

29. The method of claim 28 wherein the noise threshold is set using an ambient noise level on a signal from the microphone during a period of time that a user is not talking.