| 摘要 |
<p>Provided is an audio signal processor that is capable of improving echo cancellation performance in situations such as in a drive-through window where the proximal sound-collection environment changes. An echo canceller (23) has an adaptive filter (41) that generates a pseudo-echo signal based on a far-end signal, and a coefficient update control part (43) that causes the echo canceller coefficient of the adaptive filter (41) to converge by means of coefficient update processing. When a vehicle detection part (9), serving as an environmental change detection part, detects the arrival of a vehicle as a change in the proximal sound-collection environment, the coefficient update control part (43) alters the coefficient update processing such that the echo canceller coefficient convergence rate is reduced according to the passage of time after the detection. The coefficient update control part (43) may reduce the NLMS step size according to the passage of time. The coefficient update control part (43) may switch the coefficient update processing so as to reduce the convergence rate; for example, it may switch from the RLS method to the NLMS method.</p> |
