Abstract: A recording/reproducing apparatus using an IC memory includes an IC memory to/from which writing/reading of an audio signal is performed; and a control circuit for controlling writing/reading of the audio signal to/from this IC memory, and its address, and for controlling, on writing and reading the audio signal to and from the IC memory, so that its address becomes ring-shaped, writing, of when a recording key is pressed, the audio signal from contiguous address to an area, within the IC memory where the writing, which has never been read is performed, and reading, of when a reproduction key is pressed, the audio signal from the head of an area within the IC memory where the writing, which has never been read, is performed.

Abstract: An apparatus and a method for encoding an input signal on the time base through orthogonal transform involves removing the correlation of signal waveform on the basis of the parameters obtained by means of linear predictive coding (LPC) analysis and pitch analysis of the input signal on the time base prior to the orthogonal transform. The time base input signal from input terminal is sent to a normalization circuit section and a LPC analysis circuit. The normalization circuit section removes the correlation of the signal waveform and takes out the residue by an LPC inverse filter and pitch inverse filter and sends the residue to an orthogonal transform circuit section. The LPC parameters from the LPC analysis circuit and the pitch parameters from the pitch analysis circuit are sent to a bit allocation calculation circuit.