Turning speech into music in a two-dimensional space by varying the bandwidth and rate of tone pulses placed along formant tracks

Abstract

A two-dimensional space is introduced which changes sounds from speech-like to music-like by varying the rate and the bandwidth (decay-time) of individual tones placed along formant contours. At one extreme of a very fast pulse rate and a long decay time, the sounds are equivalent to sine-wave speech. With a more moderate tone rate and a short decay time, the sounds become monotone (at the tone-rate) speech. For tone rates around 10/s with long decay times, individual musical tones are heard at the formant frequencies. Intelligibility is poor for such sounds because of the low sampling rate of the formant contours. Increasing the tone rate and decreasing tone decay time increases intelligibility and makes the sounds less music like. Intelligibility data together with speech-like and music-like ratings of sounds from this space will be presented.