Temporal change in memory of human voice
Hiroshi Kido, Hideki Kasuya · The Journal of the Acoustical Society of America · 2004
This study investigates the extent to which human subjects accurately retain memory of speaker individuality and voice quality of utterances without receiving instruction to memorize them. Experiments constituted three phases. In phase one, 27 subjects listened to two target utterances in a paired-comparison test that required only a similarity judgment of voice quality. The target utterances were one sentence read by two males with average and characteristic voice quality, respectively, who were selected from 109 males. In phase two, performed 21 days after phase one, the same subjects evaluated Japanese expressions of voice quality [Proc. ICSLP-98, No. 1005] of the two previous target utterances based on memory only and judged with a degree of confidence whether each of seven speech stimuli (two targets and five additional speakers’ utterances) was identical to one of the two targets. In the final phase, conducted immediately after phase two, the subjects repeated the same phase-two task but after listening to the two target utterances. Data processing based on the signal detection theory revealed that temporal change in memory of speaker individuality and voice quality was relatively small over a period of 21 days. Experiments over a longer period of time are now underway.