Shuichi Yoshikawa

Automatic sound gain control device and a sound recording/reproducing device including arithmetic processor conducting a non-linear conversion

A sound gain control device for automatically controlling a gain by which an output signal from a sound CODEC is multiplied is provided. Sound signals from a sound input device are processed by a non-linear conversion circuit so that the sound signals with small amplitudes are enlarged by extending the amplitudes and the time axis thereof, thereby to average the incidence probabilities of amplitudes. Then, a proper amplitude for a gain control is calculated based on the averaged signals by an amplitude calculating circuit, and a gain corresponding to the calculated amplitude is determined by a gain determining circuit and sent as a amplitude coefficient to a multiplier to which the sound signals from the sound input device are input through a sound CODEC.

Signal reproducing device for reproducting voice signals with storage of initial valves for pattern generation

In a signal reproducing device for reproducing voice signals from vector-quantized coded data, transferred or recorded coded data is extracted one by one, and the coded data extracted are given as initial values to a recurrence equation to generate a pattern composed of a predetermined number of data for every initial value. The thus generated patterns are sequentially output as reproduction data.