Botte M C, Charron S, Bouayad H
Laboratory of Experimental Psychology (CNRS U.R.A. 316), Paris, France.
J Acoust Soc Am. 1993 Mar;93(3):1524-34. doi: 10.1121/1.406810.
Two experiments studied the frequency pattern of TLS (temporary loudness shift) as a function of the level and frequency of the fatiguing sound. In experiment 1, the fatiguing tones were intermittent 375-, 1500-, or 3000-Hz tones (10 s on/10 s off) at 75, 80, 85, 90, or 95 dB SPL. The TLS patterns were established for a continuous, 60-phon test tone at different frequencies presented simultaneously with the intermittent fatiguing tone. In experiment 2, a 1000-Hz exposure tone with an intermittency of 10 s on/20 s off was used with a continuous 60-dB test tone at different frequencies. In both experiments, the total exposure duration was 60 s; TLS was measured 5 s after the exposure ended. For the lowest two exposure levels, the TLS pattern had one peak centered on the exposure frequency. As the exposure level increased, a two-peak pattern became evident, with the second peak at higher test frequencies. This finding could be interpreted as psychoacoustical evidence for the double (passive and active) mode of displacement of the basilar membrane. In experiment 2, a TTS (temporary threshold shift) measurement after exposure to a 45-min, 1000-Hz tone at 90 dB was added to the TLS sessions. The correlations between maximum TTS after a 45-min exposure and the TLS obtained after a 60-s exposure were calculated for each of the exposure levels and test frequencies used in TLS measurements. The correlation reached as high as 0.9 for TLSs measured at 1120 Hz after a 90-dB exposure; it was smaller but significant for TLSs at the exposure frequency. Despite these correlations, differences in the overall patterns of TTS and TLS suggest that they stem from two different mechanisms.
两项实验研究了暂时性响度偏移（TLS）的频率模式与疲劳声音的声级和频率之间的函数关系。在实验1中，疲劳音是75、80、85、90或95 dB SPL的间歇性375 Hz、1500 Hz或3000 Hz音调（10秒开/10秒关）。针对与间歇性疲劳音同时呈现的不同频率的连续60方测试音，建立了TLS模式。在实验2中，使用间歇性为10秒开/20秒关的1000 Hz暴露音与不同频率的连续60 dB测试音。在两个实验中，总暴露持续时间均为60秒；在暴露结束后5秒测量TLS。对于最低的两个暴露水平，TLS模式有一个以暴露频率为中心的峰值。随着暴露水平的增加，双峰值模式变得明显，第二个峰值出现在更高的测试频率处。这一发现可以被解释为基底膜位移的双重（被动和主动）模式的心理声学证据。在实验2中，在TLS实验环节之后，增加了在90 dB下暴露于45分钟1000 Hz音调后的暂时性阈移（TTS）测量。针对TLS测量中使用的每个暴露水平和测试频率，计算了45分钟暴露后的最大TTS与60秒暴露后获得的TLS之间的相关性。在90 dB暴露后，在1120 Hz测量的TLS相关性高达0.9；在暴露频率处的TLS相关性较小但显著。尽管存在这些相关性，但TTS和TLS的总体模式差异表明它们源于两种不同的机制。
