Ward L M, Davidson K P
Department of Psychology, University of British Columbia, Vancouver, Canada.
J Acoust Soc Am. 1993 Nov;94(5):2587-94. doi: 10.1121/1.407370.
Weber fractions for sound intensity were measured for 70-, 100-, 200-, 1000-, and 10,000-Hz tone pulses at sound-pressure levels (SPLs) ranging from just above individual listeners' absolute thresholds to near their highest tolerable SPLs, using a two-alternative forced-choice adaptive staircase technique governed by a 1-up, 3-down rule. Results for four listeners with normal hearing and varying experience, despite individual differences in absolute values, showed Weber fractions that declined as sound pressure increased above threshold and asymptoted at intermediate SPLs. A power function with a negative exponent describes the data of the individual listeners better than a logarithmic function does. The absolute value of the exponent of the power function, which measures the curvature of the function, was largest at 70 Hz and declined with increasing frequency, similar to how exponents of power functions relating loudness judgments or simple reaction time to stimulus intensity differ with sound frequency.
我们使用由“1上，3下”规则控制的二选一强制选择自适应阶梯技术，在从略高于个体听众的绝对阈值到接近其最高可耐受声压级（SPL）的声压水平范围内，测量了70赫兹、100赫兹、200赫兹、1000赫兹和10000赫兹纯音脉冲的韦伯分数。尽管听力正常且经验各异的四位听众的绝对值存在个体差异，但结果显示，韦伯分数随着声压高于阈值而下降，并在中等声压级时趋于平稳。与对数函数相比，具有负指数的幂函数能更好地描述个体听众的数据。幂函数指数的绝对值衡量了函数的曲率，在70赫兹时最大，并随频率增加而下降，这类似于响度判断或简单反应时间与刺激强度的幂函数指数随声频的变化情况。
