Department of Otorhinolaryngology, The First Hospital of Dalian Medical University, Dalian, Liaoning, China (mainland).
Department of Communicative Disorders and Sciences, Center for Hearing and Deafness, State University of New York at Buffalo, Buffalo, NY, USA.
Med Sci Monit. 2022 Apr 9;28:e936373. doi: 10.12659/MSM.936373.
Loudness recruitment is a common symptom of hearing loss induced by cochlear lesions, which is defined as an abnormally fast growth of loudness perception of sound intensity. This is different from hyperacusis, which is defined as "abnormal intolerance to regular noises" or "extreme amplification of sounds that are comfortable to the average individual". Although both are characterized by abnormally high sound amplification, the mechanisms of occurrence are distinct. Damage to the outer hair cells alters the nonlinear characteristics of the basilar membrane, resulting in aberrant auditory nerve responses that may be connected to loudness recruitment. In contrast, hyperacusis is an aberrant condition characterized by maladaptation of the central auditory system. Peripheral injury can produce fluctuations in loudness recruitment, but this is not always the source of hyperacusis. Hyperacusis can also be accompanied by aversion to sound and fear of sound stimuli, in which the limbic system may play a critical role. This brief review aims to present the current status of the neurobiological mechanisms that distinguish between loudness recruitment and hyperacusis.
响度增长是由耳蜗病变引起的听力损失的常见症状，其定义为声音强度感知的异常快速增长。这与听觉过敏不同，后者定义为“对常规噪声异常不耐受”或“对普通人舒适的声音进行极端放大”。虽然两者都表现为异常高的声音放大，但发生机制是不同的。外毛细胞的损伤改变了基底膜的非线性特征，导致异常的听神经反应，这可能与响度增长有关。相比之下，听觉过敏是一种异常状态，其特征是中枢听觉系统的适应不良。外周损伤会引起响度增长的波动，但这并不总是听觉过敏的根源。听觉过敏也可能伴随着对声音的厌恶和对声音刺激的恐惧，其中边缘系统可能发挥关键作用。本文简要综述了区分响度增长和听觉过敏的神经生物学机制的最新进展。
