We have developed an intelligible high-speed speech rate conversion technology using the acoustic feature quantities that contribute to prosody. In contrast to the conventional method, which plays back accelerated speech at the same uniform rate from the beginning to end, our proposed approach varies the playback rate adaptively on the basis of acoustic detection of the position of an utterance and any fluctuations in a speaker's fundamental frequency (F0) and power. In so doing, we hope to make high-speed playback easier to listen to by providing the listener with a "slowed-down" playback ...