| 摘要 |
PROBLEM TO BE SOLVED: To provide an adapter device for hands-free speech for properly performing deciding processing on whether a transmission and reception signal is a speech signal or not and controlling the attenuator of the transmission and reception signal path based on the result of the decision. SOLUTION: The adapter device is provided with a transmission attenuator, a reception attenuator and a CPU processing block for controlling attenuation of them. The CPU processing block includes a voice presence/absence detection part for detecting transmission and reception based on the voice signal level of a transmission and reception voice path, a voice path control part for control the attenuation of the transmission and reception attenuators based on the detecting result of the voice presence/absence detection part, and a CPU for controlling the voice presence/absence detection part and the voice path control part. The voice presence/absence detection part updates an average in a long section of a voice signal level by using an average in the short section and detects it by using the average of the newest long section, the average of the newest short section and a prescribed voice detection parameter. Syllable detection processing can be used for voice presence/absence detection in addition. |
