Signal processing apparatus and signal processing method

• US 7,054,452 B2
• Filed: 08/24/2001
• Issued: 05/30/2006
• Est. Priority Date: 08/24/2000
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Ukita, Masakazu
• Primary Examiner(s): PENDLETON, BRIAN T
• Application Number:
  US09/938,787
• Publication Number:
  US 20020048376A1
• Time in Patent Office: 1,740 Days
• Field of Search: 381/92, 381/122
• US Class Current: 381/92
• CPC Class Codes: H04N 7/15 Conference systems
• CPC Class Codes: H04R 1/406 microphones
• CPC Class Codes: H04R 2499/13 Acoustic transducers and sound field adaptation in vehicles
• CPC Class Codes: H04R 3/005 for combining the signals of two or more microphones specially adapted for hearing aids H04R25/407

Abstract

The invention provides a method and apparatus by which the direction in or the position at which a signal source such as a sound source is present is estimated. A signal or signals from a signal source or a plurality of signal sources are received by a plurality of reception apparatus, and the received signals are decomposed into signals of different frequency bands by a plurality of band-pass filters. Then, cross correlation functions between the different frequency band signals are calculated for individual combinations of the reception apparatus for the individual corresponding frequency bands. If the power of noise having no directivity is high in some of the frequency bands, then the cross correlation functions of the frequency band do not exhibit a maximum value. Therefore, an influence of the noise can be suppressed effectively when delay times of the individual reception apparatus which depend upon the direction or directions or the position or positions of the signal source or sources are estimated.

Claims

1. A signal processing apparatus for processing a plurality of received signals obtained by receiving a signal or signals from at least one signal source through a plurality of reception apparatus, comprising:

first means for decomposing each of the received signals into a plurality of different frequency band signals;

second means for calculating cross correlation functions between the different frequency band signals originating from two different ones of said reception apparatus for individual corresponding frequency bands for individual possible combinations of said reception apparatus; and

third means for estimating at least one direction or at least one position of the at least one signal source based on the cross correlation functions;

wherein said third means includes;

maximum value detection means for determining delay times with which the cross correlation functions exhibit maximum values for the individual frequency bands for the individual combinations of the reception apparatus and setting the determined delay times as candidate delay times; and

estimation means for estimating the number and the at least one direction or the at least one position of the at least one signal source so that the candidate delay times may be provided most consistently.

2. A signal processing apparatus for processing a plurality of received signals obtained by receiving a signal or signals from at least one signal source through a plurality of reception apparatus, comprising:

first means for decomposing each of the received signals into a plurality of different frequency band signals;

second means for calculating cross correlation functions between the different frequency band signals originating from two different ones of said reception apparatus for individual corresponding frequency bands for individual possible combinations of said reception apparatus; and

third means for estimating at least one direction or at least one position of the at least one signal source based on the cross correlation functions;

wherein said third means includes;

normalization means for normalizing the cross correlation functions for the individual frequency bands;

addition means for adding the cross correlation functions normalized for the individual combinations of said reception apparatus over all or some plurality of ones of the frequency and

estimation means for estimating the at least one direction or the at least one position of the at least one signal source based on results of the addition of the normalized cross correlation functions; and

wherein said estimation means determines the delay times with which the cross correlation functions added by said addition means exhibit maximum values for the individual combinations of said reception apparatus and sets the determined delay times as candidate delay times and then estimates the number and the at least one direction or the at least one position of the at least one signal source with which the candidate delay times are provided most consistently.

3. A signal processing method for processing a plurality of received signals obtained by receiving a signal or signals from at least one signal source through a plurality of reception apparatus, comprising:

a first step of decomposing each of the received signals into a plurality of different frequency band signals;

a second step of calculating cross correlation functions between the different frequency band signals originating from two different ones of said reception apparatus for individual corresponding frequency bands for individual possible combinations of said reception apparatus; and

a third step of estimating at least one direction or at least one position of the at least one signal source based on the cross correlation functions;

wherein the third step includes;

a maximum value detection step of determining delay times with which the cross correlation functions exhibit maximum values for the individual frequency bands for the individual combinations of the reception apparatus and setting the determined delay times as candidate delay times; and

an estimation step of estimating the number and the at least one direction or the at least one position of the at least one signal source so that the candidate delay times may be provided most consistently.

4. A signal processing method for processing a plurality of received signals obtained by receiving a signal or signals from at least one signal source through a plurality of reception apparatus, comprising:

a first step of decomposing each of the received signals into a plurality of different frequency band signals;

a first step of decomposing each of the received signals into a plurality of different frequency band signals;

a second step of calculating cross correlation functions between the different frequency band signals originating from two different ones of said reception apparatus for individual corresponding frequency bands for individual possible combinations of said reception apparatus; and

a third step of estimating at least one direction or at least one position of the at least one signal source based on the cross correlation functions;

wherein the third step includes;

a normalization step of normalizing the cross correlation functions for the individual frequency bands;

an addition step of adding the cross correlation functions normalized for the individual combinations of said reception apparatus over all or some plurality of ones of the frequency bands; and

an estimation step of estimating the at least one direction or the at least one position of the at least one signal source based on results of the addition of the normalized cross correlation functions; and

wherein, in the estimation step, the delay times with which the cross correlation functions added by the addition step exhibit maximum values are determined for the individual combinations of said reception apparatus and the determined delay times are set as candidate delay times and then the number and the direction or the at least one position of the at least one signal sources with which the candidate delay times are provided most consistently are estimated.