JPS5517875A - Sound time base compression and expansion reproducing device - Google Patents

Abstract

PURPOSE: To expand sound signals, where the time base is compressed by a tape recorder, to sound signals having the same pitch as original sound, by controlling the read and the write of sound reproducing signals onto a memory element by clocks of the frequency according to recording and reproducing speed rates.

CONSTITUTION: Sound signals recorded on a tape recorder in recording speed v₀ are reproduced in reproducing speed v=nv₀ and have the time base compressed. These compressed signals are wrtten in BBD-A through switch S₄, which is switched by the gate signal outputted from switch control circuit 70, by clocks of frequency nf₀ generated by frequency converter circuit 60, where reproducing speed signals are applied, and are read out by clocks of frequency f₀ generated by oscillator circuit 50, and expanded reproducing sound has the same pitch as the original sound. The write and read speed is controlled similarly for other BBD-B and BBD- C parallel with BBD-A, and the pitch of the compressed and expanded reproducing sound can be made equal to the pitch of the original sound.

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