In-situ voice reinforcement system

• US 20070118360A1
• Filed: 11/22/2005
• Published: 05/24/2007
• Est. Priority Date: 11/22/2005
• Status: Active Grant

• Current Assignee: Blackberry Limited
• Original Assignee: 8758271 Canada Inc. (Blackberry Limited)
• Inventors: Escott, Alex, Hetherington, Phillip
• Granted Patent: US 9,190,069 B2
• Time in Patent Office: Days
• US Class Current: 704/206
• CPC Class Codes: G10L 21/0208 Noise filtering
• CPC Class Codes: G10L 21/0232 Processing in the frequency domain
• CPC Class Codes: G10L 21/0264 characterised by the type of parameter measurement, e.g. correlation techniques, zero crossing techniques or predictive techniques
• CPC Class Codes: G10L 21/0364 for improving intelligibility

Abstract

A voice reinforcement system extracts a portion of a converted speech signal and redirects it towards a listening area where it may be added with the original signal. The system includes a speech input, a filter, and a converter. The speech input generates an intermediate signal from a speech signal. The filter extracts a portion of the signal extending above a cutoff frequency. The converter converts the filtered signal to an aural signal directed towards a listening area.

Claims

1. A voice reinforcement system, comprising:

a speech input that converts a speech signal into an intermediate signal;

a filter that passes a substantial portion of the intermediate signal extending above a cutoff frequency; and

a converter that converts the filtered portion of the intermediate signal into an aural signal substantially in phase with the speech signal.

2. The system of claim 1, further comprising a concave parabolic surface that directs the speech signal to the speech input.

3. The system of claim 2, wherein the concave parabolic surface directs a portion of the speech signal to a sound destination.

4. The system of claim 2, where the speech input is positioned below the concave parabolic surface.

5. The system of claim 4, where the speech input comprises a first microphone and second microphone spaced apart and configured to exploit a lag time of a signal that may arrive at the different microphones.

6. The system of claim 5, further comprising an amplifier that amplifies the filtered intermediate signal before it is received by the converter.

7. The system of claim 6, further comprising a noise detector coupled to the speech input that detects a background noise.

8. The system of claim 7, where the noise detector calculates a signal to noise ratio.

9. The system of claim 7, further comprising a noise attenuator that substantially removes a continuous noise from the intermediate signal.

10. The system of claim 9, where the cutoff frequency is in the range from about 2000 Hertz to about 4000 Hertz.

11. The system of claim 1, further comprising a concave spherical surface that directs the speech signal to the speech input.

12. The system of claim 11, wherein the concave spherical surface directs a portion of the speech signal to a sound destination.

13. The system of claim 11, where the speech input is positioned below the concave spherical surface.

14. The system of claim 13, where the speech input is positioned at a radial center of the concave spherical surface.

15. A method for increasing the intelligibility of a speech signal, comprising:

converting a speech signal into an intermediate signal;

filtering a portion of the intermediate signal to dampen the signal extending above a cutoff frequency;

converting the filtered portion of the intermediate signal into an aural signal; and

summing the filtered portion of the intermediate signal with the speech signal.

16. The method of claim 15, further comprising amplifying the filtered intermediate signal before it is received by the converter.

17. The method of claim 16, where the act of amplifying the filtered intermediate signal comprises manually configuring a level of amplification.

18. The method of claim 16, further comprising estimating a background noise.

19. The method of claim 18, further comprising removing a substantial portion of the background noise.

20. A voice reinforcement system comprising:

means for converting a speech signal into an intermediate signal;

means for filtering a portion of the intermediate signal extending above a cutoff frequency; and

means for converting the filtered portion of the intermediate signal into an aural signal substantially in phase with the speech signal.