Title:
DYNAMIC BALANCE CONTROL FOR TELEPHONE
Document Type and Number:
WIPO Patent Application WO/2004/105357
Kind Code:
A2
Abstract:
A telephone includes a transmit channel and a receive channel, each including a bank of sub-band filters having a VAD coupled one to each sub-band filter. Each VAD measures the spectral energy in a sub-band, compares the spectral energy to a first threshold, and produces an output signal representative of whether or not the first threshold is exceeded. The voice activity detector also includes a threshold circuit for calculating a dynamically adjustable noise threshold based upon averaged measured spectral energy. A wide band or system VAD monitors echo canceling circuitry to detect voice activity and double talk. A dynamic balance control circuit (Fig. 19) maintains the transmit and receive channels in a predetermined energy ratio (191) during double talk.
Inventors:
MIKESELL JAMES R
STORY FRANKLYN H
STORY FRANKLYN H
Application Number:
PCT/US2004/015607
Publication Date:
December 02, 2004
Filing Date:
May 19, 2004
Export Citation:
Assignee:
ACOUSTIC TECH INC (US)
International Classes:
H04B1/38; H04M1/00; H04M9/08; H04M; (IPC1-7): H04M/
Foreign References:
| US6442275B1 | 2002-08-27 |
Attorney, Agent or Firm:
Wille, Paul F. (Scottsdale, AZ, US)
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