The perception of speed-modified recordings

Abstract

The overall quality of audio tapes may be affected by such factors as background noise and the intensity of the signal, or whether the recording was made at the correct speed. The last would affect the speaking fundamental frequency (SFF), and therefore perceived pitch, and phonetic characteristics of the speech sample. Listeners’ skills regarding the recognition of recording speeds that had been manipulated are investigated here. It was found that a majority of correct identifications of speed manipulation is only achieved when the speed is –6% or +6% off the correct speed in an experimental procedure that compared deviations of 3, 6 and 9%. Judging samples that are played at higher speeds is easier than those played at lower speeds. Expert listeners did not perform any better than naive or trained listeners. However, they were more cautious and were more often correct when very confident about their judgments.