| 摘要 |
PROBLEM TO BE SOLVED: To allow an echo canceller to be able to sufficiently enhance its echo canceling performance at all times by automatically adjusting an echo return loss of a hands-free speech unit. SOLUTION: In this speech unit, an echo return loss measurement means 4 measures an echo return loss, and a gain adjustment means 5 and an inverse gain provision means 7 for automatically adjust the signal level by using the result of the measurement, so as to maximize the echo cancellation amount of an echo canceller 6. Also the echo cancellation amount by the echo canceller 6 is given to the echo return loss measurement means 4, so as to much more optimize automatic adjustment. Furthermore, a white noise generating means 8 is provided to the speech unit to attain more suitable echo return loss adjustment. |
