Predictable sequential structure augments auditory sensitivity at threshold

Abstract

Human hearing is highly sensitive and allows us to detect acoustic events at low levels and at great distances. However, sensitivity is not only a function of the integrity of cochlear mechanisms, but also constrained by central processes such as attention and expectation. While the effects of distraction and attentional orienting are generally acknowledged, the extent to which probabilistic expectations influence sensitivity is not clear. Classical audiological assessment, commonly used to assess hearing sensitivity, does not distinguish between bottom-up sensitivity and top-down gain/filtering. In this study, we aim to decipher the influence of various types of expectations on hearing sensitivity and how this information can be used to improve the assessment of sensitivity to sound. Our results raise important critiques regarding common practices in the assessment of sound sensitivity, both in fundamental research and in audiological clinical assessment.Significance StatementThe principal clinical measure of ear function is the pure-tone audiogram in which a clinician will test for the softest tones one can detect across the frequency range. Clinicians have long known listener strategy can influence these measures whereby patients can guess when tones may occur based on regularities in the tone presentation structure. Our results demonstrate that this predictability and other forms influence not only listener strategy but also the sensitivity of the peripheral auditory system itself. This finding that prediction not only biases low-level perception but also enhances it has wide-ranging consequences for the fields of audiology and cognitive neuroscience, and furthermore suggests that prediction ability should be tracked as well as ear sensitivity as patients age.