Nicola J. Fedele

Low-energy-content voice detection apparatus

An apparatus for detecting and storing digital data corresponding to spoken words carried by acoustic signals includes apparatus for detecting and storing the unvoiced portion of speech which often precedes the voiced portion of a word, even where the amplitude of the unvoiced portion is comparable to the background noise level. The apparatus includes dynamic storage which holds data corresponding to a fixed time period prior to detection of the larger-amplitude voiced segment. Voiced speech is detected when it exceeds a stored value related to the average background noise. At the instant of this detection, the segment of prior data held in the dynamic storage is retained for analysis as unvoiced speech.