Alterations in auditory processing of speech stimuli during aging in healthy subjects

Studies of auditory processing during aging in man have not provided a consensus on whether aging affects the ability to process speech stimuli. To evaluate the relationship between speech recognition tasks and age, we examined 36 male subjects between the ages of 21 and 83 years, who were screened for the absence of disease, particularly in the cardiovascular and neurologic systems. Measures were obtained on the following tests: pure tone thresholds, speech reception threshold, speech discrimination, low-pass filtered speech, and binaural fusion. A statistically significant correlation was found between pure tone thresholds and age for all frequencies. When the effect of peripheral hearing loss was taken into account, speech measures did not correlate with age, with the exception of low-pass filtered speech in the left ear. Our findings suggest that the aging process in healthy man is not necessarily accompanied by deficits in the processing of speech stimuli beyond those which are due to peripheral hearing loss.