Lopez-Poveda Enrique A, Alves-Pinto Ana
Unidad de Audición Computacional y Psicoacústica, Instituto de Neurociencias de Castilla y León, Universidad de Salamanca, 37007 Salamanca, Spain.
J Acoust Soc Am. 2008 Mar;123(3):1544-54. doi: 10.1121/1.2835418.
Recent studies have suggested that the degree of on-frequency peripheral auditory compression is similar for apical and basal cochlear sites and that compression extends to a wider range of frequencies in apical than in basal sites. These conclusions were drawn from the analysis of the slopes of temporal masking curves (TMCs) on the assumption that forward masking decays at the same rate for all probe and masker frequencies. The aim here was to verify this conclusion using a different assumption. TMCs for normal hearing listeners were measured for probe frequencies (f(P)) of 500 and 4000 Hz and for masker frequencies (f(M)) of 0.4, 0.55, and 1.0 times the probe frequency. TMCs were measured for probes of 9 and 15 dB sensation level. The assumption was that given a 6 dB increase in probe level, linear cochlear responses to the maskers should lead to a 6 dB vertical shift of the corresponding TMCs, while compressive responses should lead to bigger shifts. Results were consistent with the conclusions from earlier studies. It is argued that this supports the assumptions of the standard TMC method for inferring compression, at least in normal-hearing listeners.
最近的研究表明，频率外周听觉压缩程度在蜗顶和蜗底耳蜗部位相似，并且压缩在蜗顶比在蜗底扩展到更宽的频率范围。这些结论是基于时间掩蔽曲线（TMC）斜率的分析得出的，其假设是对于所有探测音和掩蔽音频率，前向掩蔽以相同速率衰减。这里的目的是使用不同假设来验证这一结论。对听力正常的受试者测量了500和4000Hz探测频率（f(P)）以及0.4、0.55和1.0倍探测频率的掩蔽频率（f(M)）的TMC。测量了9和15dB感觉级的探测音的TMC。假设给定探测音强度增加6dB，对掩蔽音的线性耳蜗反应应导致相应TMC垂直移动6dB，而压缩反应应导致更大的移动。结果与早期研究的结论一致。有人认为，这支持了标准TMC方法用于推断压缩的假设，至少在听力正常的受试者中是如此。
