On the comprehension of extremely fast synthetic speech

Abstract

We report on a pilot study testing the subjective comprehension of tempo-scaled synthetic speech with 9 sighted and 2 blind students. German texts (length, 100 words) were generated with a formant synthesizer and a diphone synthesizer at seven different tempo steps from 3.5 syllables per second (s/s) to 17.5 s/s. The results show that the blind subjects can understand formant synthesis at all offered rates, whereas the performance of their sighted peers declines at a rate of 10.5 s/s. Contrary to our expectations, diphone synthesis is less easy to understand than formant synthesis for both groups at rates faster than 7.5 s/s. The potential reasons for these two main findings are discussed.