Patent Number: 7,787,613

Title: Method and apparatus for double-talk detection in a hands-free communication system

Abstract: An echo canceling circuit comprising a double talk detector, an upper band signal filter configured to pass only near-end upper band signals to the double talk detector and remove lower band signals, an adaptive filter circuit, a control circuit operatively coupled to the double talk detector and to the adaptive filter circuit, and a threshold estimator configured to iteratively calculate an upper adaptive decision threshold value and a lower adaptive decision threshold value. The double talk detector declares near-end speech to be present if an estimated power level of the upper band signals exceeds the upper adaptive decision threshold value, and declares the near-end speech to be absent if the estimated power level of the upper band signals falls below the lower adaptive decision threshold value for a predetermined number of iterative cycles.

Inventors: Cruz-Zeno; Edgardo M. (Round Lake, IL), Piket; James B. (Gilbert, AZ), Ramabadran; Tenkasi V. (Naperville, IL)

Assignee: Motorola, Inc.

International Classification: H04M 9/08 (20060101)

Expiration Date: 8/31/12018