| 摘要 |
<p>An echo in an electrical audio signal is reduced by converting a first acoustic signal into the electrical audio signal, generating an echo estimate signal from a loudspeaker signal, and generating an error signal that is a difference between the electrical audio signal and the echo estimate signal. A residual echo contained in the echo estimate signal is then reduced by decorrelating the error signal. Decorrelation may be performed by differentiating the echo estimate signal with respect to time. To avoid decorrelating wanted components in the error signal (e.g., audio components associated with a near-end user), decorrelation of the error signal may be applied only when a magnitude of the error signal is in a range defined by positive and negative threshold levels. The positive and negative threshold levels may be determined as a function of the echo estimate signal. For example, the threshold levels may be derived from an envelope of the echo estimate signal. Determining the threshold levels may be performed periodically, thereby dynamically adjusting the positive and negative threshold levels.</p> |
