System and method for babble noise detection

• US 20050267745A1
• Filed: 05/25/2004
• Published: 12/01/2005
• Est. Priority Date: 05/25/2004
• Status: Active Grant

• Current Assignee: RPX Corporation
• Original Assignee: Nokia Corporation
• Inventors: Valve, Paivi, Laaksonen, Laura
• Granted Patent: US 8,788,265 B2
• Time in Patent Office: Days
• US Class Current: 704/226
• CPC Class Codes: G10L 25/78 Detection of presence or absence of voice signals switching of direction of transmission by voice frequency in two-way loud-speaking telephone systems H04M9/10

Abstract

A method, device, system, and computer program product calculate a gradient index as a sum of magnitudes of gradients of speech signals from a received frame at each change of direction; and provide an indication that the frame contains babble noise if the gradient index, energy information, and background noise level exceed pre-determined thresholds or a voice activity detector algorithm and sound level indicate babble noise.

Claims

1. A method for detecting babble noise, the method comprising:

receiving an input signal including a speech signal;

calculating a gradient index as a sum of magnitudes of gradients of speech signals from the received input signal at each change of direction; and

providing an indication that the input signal contains babble noise if the gradient index, energy information, and background noise level exceed pre-determined thresholds.

2. The method claim 1, further comprising performing a voice activity detector algorithm to determine if the input signal contains babble noise.

3. The method of claim 2, wherein providing an indication that the input signal contains babble noise further comprises determining the input signal contains babble noise based on the gradient index, energy information, and background noise level exceeding pre-determined thresholds and/or a sound level of the input signal and the voice activity detector algorithm.

4. The method of claim 1, further comprising filtering the energy information and the gradient index.

5. The method of claim 4, wherein filtering the energy information and the gradient index is of the form

6. The method of claim 4, wherein energy information and the gradient index are filtered using an IIR filter.

7. A method for detecting babble noise, the method comprising:

receiving an input signal including a speech signal;

monitoring the input signal level using a voice activity detector algorithm;

providing an indication that the input signal contains babble noise if the input signal level falls below a predetermined threshold level.

8. A method for detecting babble noise, the method comprising:

receiving an input signal including a speech signal;

calculating a gradient index as a sum of magnitudes of gradients of speech signals from the received input signal at each change of direction;

monitoring the input signal level using a voice activity detector algorithm; and

providing an indication that the input signal contains babble noise if the input signal level falls below a predetermined threshold level or if the gradient index, energy information, and background noise level exceed predetermined thresholds.

9. A communication device that detects babble noise in speech signals, the device comprising:

an interface that communicates with a wireless network; and

programmed instructions stored in a memory and configured to detect babble noise based on a spectral distribution of noise.

10. The device of claim 9, wherein the spectral distribution of noise comprises checking if a gradient index, energy information, and background noise level exceed pre-determined thresholds.

11. The device of claim 9, further comprising programmed instructions to detect babble noise based on a voice activity detector algorithm.

12. The device of claim 9, wherein the detection of babble noise requires only one frame of speech signal.

13. A device in a communication network that detects babble noise in speech signals, the device comprising:

an interface that sends and receives speech signals; and

programmed instructions stored in a memory and configured to detect babble noise based on a voice activity detector algorithm.

14. The device of claim 13, further comprising programmed instructions to detect babble noise based on a gradient index, energy information, and background noise level exceeding pre-determined thresholds.

15. The device of claim 14, further comprising filtering the energy information and the gradient index.

16. A system for detecting babble noise, the system comprising:

means for receiving a communication signal including a speech signal;

means for calculating a gradient index as a sum of magnitudes of gradients of speech signals from the received communication signal at each change of direction; and

means for providing an indication that the communication signal contains babble noise if the gradient index, energy information, and background noise level exceed pre-determined thresholds.

17. The system of claim 16, further comprising means for determining the communication signal contains babble noise based on the gradient index, energy information, and background noise level exceeding pre-determined thresholds and/or a sound level of the communication signal and a voice activity detector algorithm.

18. The system of claim 17, further comprising means for detecting babble noise when the voice activity detector algorithm or the gradient index, energy information, and background noise level exceeds pre-determined thresholds is a false positive result.

19. A computer program product that detects babble noise, the computer program product comprising:

computer code to;

calculate a gradient index as a sum of magnitudes of gradients of speech signals from a received input signal at each change of direction; and

provide an indication that the input signal contains babble noise if the gradient index, energy information, and background noise level exceed pre-determined thresholds or a voice activity detector algorithm and sound level indicate babble noise.

20. The computer program product of claim 19, wherein if no babble noise is indicated and the voice activity detector algorithm indicates babble noise after a period of time and the gradient index, energy information, and background noise level exceed pre-determined thresholds, provide an indication that the input signal contains babble noise.

21. The computer program product of claim 19, wherein if no babble noise is indicated and the voice activity detector algorithm indicates babble noise after a period of time and the gradient index, energy information, and background noise level do not exceed pre-determined thresholds, the computer code waits a time, updates the input signal, and checks for babble noise in the updated input signal.

22. The computer program product of claim 21, wherein the computer code further filters the gradient index and energy information.