System and method of detecting speech intelligibility of audio announcement systems in noisy and reverberant spaces

• US 20070147625A1
• Filed: 12/28/2005
• Published: 06/28/2007
• Est. Priority Date: 12/28/2005
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Shields, D., Zumsteg, Philip
• Granted Patent: US 8,103,007 B2
• Time in Patent Office: Days
• US Class Current: 381/57
• CPC Class Codes: G10L 25/69 for evaluating synthetic or decoded voice signals
• CPC Class Codes: H04R 2227/009 Signal processing in [PA] systems to enhance the speech intelligibility
• CPC Class Codes: H04R 29/007 for public address systems public address systems per se H04R27/00

Abstract

A system and method to detect and remediate unacceptable levels of speech intelligibility evaluates received test audio transmitted across and received in a space or region of interest. Intelligibility is improved by altering the rate, pitch, amplitude and frequency bands energy during presentation of the speech signal.

Claims

1. A method comprising:

sensing the ambient sound in a region for a predetermined time interval;

analyzing the sensed ambient sound;

overlaying the ambient sound with a plurality of test audio signals having predetermined characteristics;

sensing the overlaid ambient sound; and

determining if speech intelligibility in the region has been degraded beyond an acceptable standard.

2. A method as in claim 1 where the determining includes analyzing the ambient sound pressure level.

3. A method as in claim 1 where the determining includes analyzing the ambient frequency domain characteristics.

4. A method as in claim 1 which includes overlaying the ambient sound with modulated noise.

5. A method as in claim 4 which includes amplitude modulating the noise.

6. A method as in claim 5 which includes providing amplitude modulated noise for a predetermined time interval.

7. A method as in claim 5 which includes providing amplitude modulated noise of a predetermined periodicity.

8. A method as in claim 7 which providing amplitude modulated noise for a predetermined time interval.

9. A method as in claim 7 where the amplitude modulation exceeds fifty percent of signal amplitude.

10. A method as in claim 7 where the amplitude modulation exceeds ninety percent of signal amplitude.

11. A method as in claim 7 where the determining includes analyzing the maximum attainable sound pressure level.

12. A method as in claim 10 where the determining includes analyzing trailing edge characteristics of received audio test signals to measure decay time in the region.

13. A method as in claim 7 where the overlaid test signals are emitted with a predetermined maximum attainable sound pressure level.

14. A method as in claim 7 where the overlaid test signals are emitted with at least a predetermined minimum frequency bandwidth.

15. A method for remediation comprising:

determining optimum remediation for a region;

determining if current and optimum remediation differ, and if so, carrying out at least a determined optimum amplitude.

16. A method as in claim 15 which includes carrying out optimum frequency bands energy remediation.

17. A method as in claim 15 which includes carrying out optimum pace remediation.

18. A method as in claim 15 which includes carrying out optimum pitch remediation.

19. A method as in claim 15 which includes carrying out optimum amplitude of the speech message remediation.

20. A method as in claim 15 which includes varying the rate of a speech message

21. A method as in claim 15 which includes varying the pitch of a speech message

22. A method as in claim 15 which includes varying the frequency bands energy of a speech message

23. A method as in claim 15 which includes varying the amplitude of a speech message.