Department of Speech, Language, and Hearing Sciences, University of Arizona, 1131 East 2nd Street, Tucson, Arizona, 85721, USA.
J Acoust Soc Am. 2011 Jul;130(1):263-72. doi: 10.1121/1.3598448.
The form of the psychometric function (PF) for auditory frequency discrimination is of theoretical interest and practical importance. In this study, PFs for pure-tone frequency discrimination were measured for several standard frequencies (200-8000 Hz) and levels [35-85 dB sound pressure level (SPL)] in normal-hearing listeners. The proportion-correct data were fitted using a cumulative-Gaussian function of the sensitivity index, d', computed as a power transformation of the frequency difference, Δf. The exponent of the power function corresponded to the slope of the PF on log(d')-log(Δf) coordinates. The influence of attentional lapses on PF-slope estimates was investigated. When attentional lapses were not taken into account, the estimated PF slopes on log(d')-log(Δf) coordinates were found to be significantly lower than 1, suggesting a nonlinear relationship between d' and Δf. However, when lapse rate was included as a free parameter in the fits, PF slopes were found not to differ significantly from 1, consistent with a linear relationship between d' and Δf. This was the case across the wide ranges of frequencies and levels tested in this study. Therefore, spectral and temporal models of frequency discrimination must account for a linear relationship between d' and Δf across a wide range of frequencies and levels.
听觉频率辨别心理测量函数（PF）的形式具有理论意义和实际重要性。在这项研究中，在正常听力受试者中，测量了几种标准频率（200-8000 Hz）和水平[35-85 dB 声压级（SPL）]的纯音频率辨别 PF。使用灵敏度指标 d'的累积高斯函数对比例正确数据进行拟合，d'是频率差Δf的幂变换计算得出的。幂函数的指数对应于 log(d')-log(Δf)坐标上 PF 的斜率。研究了注意力失误对 PF 斜率估计的影响。当不考虑注意力失误时，log(d')-log(Δf)坐标上估计的 PF 斜率明显低于 1，表明 d'和Δf之间存在非线性关系。然而，当将失误率作为拟合的自由参数包含在内时，发现 PF 斜率与 1 没有显著差异，与 d'和Δf之间的线性关系一致。在本研究测试的宽频率和水平范围内均如此。因此，频率辨别光谱和时间模型必须在宽频率和水平范围内考虑 d'和Δf之间的线性关系。
