Spectral and temporal resolution in listeners with age-dependent hearing loss

Abstract

Two basic mechanisms perform the frequency analysis of sounds: (i) the spectral mechanism presented by a bank of frequency-tuned filters and (ii) The temporal mechanism that uses the temporal structure of the signal. The temporal structure manifests in the autocorrelation function. The roles of the spectral and temporal mechanisms in the age-dependent hearing loss were investigated using rippled-spectrum signals. It has been shown previously that discrimination of two rippled signals with different positions of ripples at the frequency scale is mostly performed the spectral processing; for discrimination between a rippled and “flat” signal, the temporal processing dominated. In cases of hearing loss, the decrease of the acuteness of frequency-tuned cochlear filters resulted in reduction of the ripple-pattern resolution by the spectral mechanism. This effect did not influence the capabilities of the temporal mechanism. However, listeners with the age-dependenthearing loss did not perceive high sound frequencies. High frequencies were more favorable for temporal processing, so the inability to perceive these frequencies negatively influenced the ripple resolution. Thus, resolution of rippled signals may reduce at any discrimination task; however, the mechanisms of the reduction differed depending on the task. [Work supported by The Russian Science Foundation, Grant 23-25-00148.]