SPEECH DECISION DEVICE AND ACOUSTIC REPRODUCTION DEVICE

摘要

PURPOSE:To provide the speech decision device which decides whether an acoustic signal is a speech or not irrelevantly to whether the acoustic signal is monaural or stereophonic and the acoustic reproducing device which automatically varies frequency characteristics according to whether or not the signal is the speech. CONSTITUTION:A power calculation part 1 calculates the power of the input signal in a frame section, a voiced/voiceless decision part 3 decides whether the frame section is voiced or voiceless judging from the calculated power, and a stationarity decision part 5 calculates the difference value between the maximum value and minimum value of the power in plural successive frame sections. Further, a zero-crossing calculation part 2 calculates the frequency of zero-crossing of the signal in the frame section and a consonant characteristic decision part 4 decides the consonant characteristic of the frame from the frequency of zero-crossing. A speech decision part 6 decides the speech when the presence rate of a voiceless frame in plural frame sections, the presence ratio of the consonant characteristic frame, and the power difference value are larger than prescribed values respectively.