Patent · US Expired

Speech presence detector based on sparse time-random signal samples

US5822726A · kind A · utility

44Cited by
12References
19Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJan 31, 1995
Grant dateOct 13, 1998
Priority date
Expiry dateJan 31, 2015

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04B1/46
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

A speech presence detector (101) includes a circuit input (105) to couple to a source of input signals. A control signal generator (113) generates control signals. A sampling circuit (112) samples the input signals as a function of the control signal. A processor (116, 616, or 916) is coupled to the sampling circuit to receive the signal samples. The processor is responsive to the sampled signals to identify a background noise threshold and detect the presence of speech. According to one embodiment, the method and apparatus employ a random control signal. According to another embodiment, the average frequency of the control signal is below the Nyquist rate. According to another embodiment, the processor is responsive to the received signal to count the number of samples within a predetermined amplitude range and identifies a background noise threshold from the number of samples which are in the predetermined range.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.