Munro Kevin J, Walker Adam J, Purdy Suzanne C
School of Psychological Sciences, University of Manchester, Manchester, UK.
Neuroreport. 2007 Aug 6;18(12):1237-40. doi: 10.1097/WNR.0b013e32822025f4.
Hearing aids can induce perceptual changes in some elderly listeners but few studies have investigated physiological changes in this population. Loudness discomfort levels and acoustic reflex thresholds were measured in long-term users of a single hearing aid. The results show an asymmetry of +2 to +9 dB between ears in the sound level that (i) causes loudness discomfort and (ii) elicits a reflex contraction of the middle ear muscles. The elevation of the acoustic reflex threshold occurs in the ear with hearing aid experience, irrespective of the ear of stimulation. Therefore, there is evidence of adaptive plasticity and this can be measured at the level of the auditory brainstem.
助听器会在一些老年听力患者中引起感知变化，但很少有研究调查这一人群的生理变化。我们对长期使用单一助听器的用户测量了响度不适阈和声反射阈值。结果显示，在引起响度不适的声级和引发中耳肌肉反射性收缩的声级之间，双耳存在2至9分贝的不对称。声反射阈值的升高出现在有佩戴助听器经历的耳朵中，与刺激耳无关。因此，有证据表明存在适应性可塑性，并且这可以在听觉脑干水平上进行测量。
