Blamey P J, Alcantara J I, Cowan R S, Galvin K L, Sarant J Z, Clark G M
Human Communication Research Centre, University of Melbourne, Australia.
J Acoust Soc Am. 1990 Oct;88(4):1765-72. doi: 10.1121/1.400197.
Gross variations of the speech amplitude envelope, such as the duration of different segments and the gaps between them, carry information about prosody and some segmental features of vowels and consonants. The amplitude envelope is one parameter encoded by the Tickle Talker, an electrotactile speech processor for the hearing impaired which stimulates the digital nerve bundles with a pulsatile electric current. Psychophysical experiments measuring the duration discrimination and identification, gap detection, and integration times for pulsatile electrical stimulation are described and compared with similar auditory measures for normal and impaired hearing and electrical stimulation via a cochlear implant. The tactile duration limen of 15% for a 300-ms standard was similar to auditory measures. Tactile gap detection thresholds of 9 to 20 ms were larger than for normal-hearing but shorter than for some hearing-impaired listeners and cochlear implant users. The electrotactile integration time of about 250 ms was shorter than previously measured tactile values but longer than auditory integration times. The results indicate that the gross amplitude envelope variations should be conveyed well by the Tickle Talker. Short bursts of low amplitude are the features most likely to be poorly perceived.
言语幅度包络的总体变化，例如不同片段的时长以及它们之间的间隙，携带着有关韵律以及元音和辅音的一些音段特征的信息。幅度包络是由“挠痒痒交谈器”编码的一个参数，这是一种用于听力受损者的电触觉言语处理器，它通过脉动电流刺激指神经束。描述了测量脉动电刺激的时长辨别与识别、间隙检测以及整合时间的心理物理学实验，并将其与正常听力和听力受损者以及通过人工耳蜗进行电刺激的类似听觉测量结果进行了比较。对于300毫秒的标准刺激，触觉时长辨别阈为15%，这与听觉测量结果相似。9至20毫秒的触觉间隙检测阈值比正常听力者的大，但比一些听力受损的听众和人工耳蜗使用者的短。约250毫秒的电触觉整合时间比之前测量的触觉值短，但比听觉整合时间长。结果表明，“挠痒痒交谈器”应该能够很好地传达总体幅度包络变化。低幅度的短脉冲串是最有可能难以被感知的特征。
