Department of Otolaryngology, The University of Melbourne, Melbourne, 3054, Australia.
J Assoc Res Otolaryngol. 2010 Mar;11(1):101-11. doi: 10.1007/s10162-009-0188-5. Epub 2009 Oct 2.
The effect of amplitude modulation of pulse trains on the loudness perceived by cochlear implantees was investigated for different overall levels of the signal, modulation depth and the carrier rate of the pulse train. Equally loud and threshold levels were determined for a variety of signal levels, modulation depths and carrier rates in six cochlear implantees. The pattern of results was consistent with the predictions of a previously published loudness model of McKay et al. (J Acoust Soc Am 113:2054-2063, 2003). The degree to which the loudness of modulated stimuli differed from the loudness elicited by an unmodulated pulse train with equivalent average current depended on the modulation depth and the absolute current level of the unmodulated stimulus. The effect of carrier rate on this measure was predictable solely from the effect of rate on absolute current level for equal loudness. The results have important implications for the interpretation of experiments measuring modulation detection that do not control loudness cues. We show that several previously published results regarding the effect of carrier rate and added noise on modulation detection could be reinterpreted in the light of these findings.
研究了脉冲串的幅度调制对人工耳蜗植入者感知响度的影响，考察了不同的信号总水平、调制深度和脉冲串载波率。在六位人工耳蜗植入者中，为各种信号水平、调制深度和载波率确定了等效响度和阈值水平。结果模式与 McKay 等人（J Acoust Soc Am 113:2054-2063, 2003）先前发表的响度模型的预测一致。调制刺激的响度与具有等效平均电流的未调制脉冲串产生的响度之间的差异程度取决于调制深度和未调制刺激的绝对电流水平。载波率对该测量值的影响可以仅根据等响度下载波率对绝对电流水平的影响来预测。这些结果对于解释不控制响度线索的调制检测实验具有重要意义。我们表明，可以根据这些发现重新解释先前关于载波率和附加噪声对调制检测影响的几项结果。
