Medizinische Physik, Universität Oldenburg, D-26111 Oldenburg, Germany.
Hear Res. 2011 Oct;280(1-2):177-91. doi: 10.1016/j.heares.2011.05.016. Epub 2011 Jun 6.
A dysfunction or loss of outer hair cells (OHC) and inner hair cells (IHC), assumed to be present in sensorineural hearing-impaired listeners, affects the processing of sound both at and above the listeners' hearing threshold. A loss of OHC may be responsible for a reduction of cochlear gain, apparent in the input/output function of the basilar membrane and steeper-than-normal growth of loudness with level (recruitment). IHC loss is typically assumed to cause a level-independent loss of sensitivity. In the current study, parameters reflecting individual auditory processing were estimated using two psychoacoustic measurement techniques. Hearing loss presumably attributable to IHC damage and low-level (cochlear) gain were estimated using temporal masking curves (TMC). Hearing loss attributable to OHC (HL(OHC)) was estimated using adaptive categorical loudness scaling (ACALOS) and by fitting a loudness model to measured loudness functions. In a group of listeners with thresholds ranging from normal to mild-to-moderately impaired, the loss in low-level gain derived from TMC was found to be equivalent with HL(OHC) estimates inferred from ACALOS. Furthermore, HL(OHC) estimates obtained using both measurement techniques were highly consistent. Overall, the two methods provide consistent measures of auditory nonlinearity in individual listeners, with ACALOS offering better time efficiency.
外毛细胞（OHC）和内毛细胞（IHC）功能障碍或丧失，据推测存在于感音神经性听力受损的听众中，这会影响声音的处理，无论是在听众的听力阈值以下还是以上。OHC 的丧失可能导致耳蜗增益降低，在基底膜的输入/输出函数中表现明显，响度随水平（募集）的增长比正常情况下更陡峭。IHC 损失通常被认为导致灵敏度的非水平依赖性损失。在当前的研究中，使用两种心理声学测量技术估计了反映个体听觉处理的参数。使用时变掩蔽曲线（TMC）估计归因于 IHC 损伤和低水平（耳蜗）增益的听力损失。使用自适应分类响度标度（ACALOS）和拟合响度模型来测量响度函数来估计归因于 OHC 的听力损失（HL（OHC））。在一组从正常到轻度到中度受损的听众中，发现 TMC 得出的低水平增益损失与 ACALOS 推断的 HL（OHC）估计值相当。此外，使用这两种测量技术获得的 HL（OHC）估计值高度一致。总体而言，这两种方法为个体听众提供了一致的听觉非线性测量，ACALOS 提供了更好的时间效率。
