Smits J T, Duifhuis H
Audiology. 1982;21(4):310-24. doi: 10.3109/00206098209072746.
3 listeners with sensorineural hearing loss ranging from moderate to moderate-severe starting at frequencies higher than 1 kHz participated in two masking experiments and a partial masking experiment. In the first masking experiment, fM = 1 KHz and LM = 50 dB SPL, higher than normal masked thresholds were obtained for listeners whose hearing was impaired in the frequency region of clear hearing loss as well as in the region of near-normal absolute thresholds. The second masking experiment showed that for hearing-impaired listeners the elevation of the masked thresholds, in decibels, in this frequency region of "near-normal' absolute thresholds was equal to the elevation of the absolute thresholds, in decibels. The third experiment, a partial masking experiment with fM = 975-1025 Hz and LM = 75 dB SPL, showed similar partial-masking functions for hearing-impaired and normal listeners, but the functions for the hearing-impaired listeners were at much higher levels of the partially masked probe tone. Thus the higher masked thresholds of the hearing-impaired can result in a dramatic reduction of the dynamic range of hearing under masking in the frequency region of the hearing loss and also in the region with only a small hearing loss (less than 30 dB). It is suggested that this may explain the speech perception difficulties which these listeners experience, especially in the presence of ambient noise.
3名感音神经性听力损失程度从中度到中重度、起始频率高于1kHz的受试者参与了两项掩蔽实验和一项部分掩蔽实验。在第一个掩蔽实验中，掩蔽频率fM = 1kHz，掩蔽级LM = 50dB SPL，对于在明显听力损失频率区域以及绝对阈值接近正常区域听力受损的受试者，获得了高于正常的掩蔽阈值。第二个掩蔽实验表明，对于听力受损的受试者，在“接近正常”绝对阈值的这个频率区域，掩蔽阈值以分贝为单位的升高量与绝对阈值以分贝为单位的升高量相等。第三个实验是一个部分掩蔽实验，fM = 975 - 1025Hz，LM = 75dB SPL，结果显示听力受损受试者和正常受试者具有相似的部分掩蔽函数，但听力受损受试者的函数对应的部分掩蔽探测音水平要高得多。因此，听力受损者较高的掩蔽阈值会导致在听力损失频率区域以及仅存在轻微听力损失（小于30dB）的区域中，掩蔽情况下听力动态范围大幅减小。有人认为，这可能解释了这些受试者在言语感知方面遇到的困难，尤其是在存在环境噪声的情况下。
