A disk administrating system is provided for administrating multiple disk-arrays containing at least one disk array. Further, there is provided a capacitor across which an AC component is taken out from the output side of a power amplification transistor in the final amplification stage of the high frequency power amplifier circuit to be thereby impressed to the interior of the output power detection circuit. A time-synchronous speech recognition pass is performed using a decoding search to determine a recognition output corresponding to the speech input.