| 摘要 |
PCT No. PCT/GB96/00344 Sec. 371 Date Aug. 13, 1997 Sec. 102(e) Date Aug. 13, 1997 PCT Filed Feb. 15, 1996 PCT Pub. No. WO96/25733 PCT Pub. Date Aug. 22, 1996A voice activity detector has an input for receiving an outgoing speech signal transmitted from a speech system to a user and an input for receiving an incoming signal from the user. Both the outgoing and incoming signals are divided into time limited frames. A feature is calculated from each frame of the incoming signal and for forming a function of the calculated feature and a threshold. Based on the function, it is determined whether or not the incoming signal includes speech. Means are provided to determine the echo return loss during an outgoing speech signal from the interactive speech system and to control the threshold in dependence on the echo return loss measured. |
