DOES AGING AFFECT THE CHANNEL CAPACITY FOR IDENTIFYING PURE TONES DIFFERING ONLY IN INTENSITY?

Abstract

Murphy et al. (2006) showed that normal-hearing younger and older adults do not differ in their ability to identify a set of eight pure-tones differing in intensity only (52, 58, 64, 70, 76, 82, 88, and 94 dB SPL). Their results suggest that auditory channel-capacity is preserved in aging. However, it is possible that using perfectly discriminable stimuli did not allow age-related differences to surface in Murphy et al’s experiment. In the current study, we repeated Murphy et al’s experiment using more closely spaced stimuli (60, 61.5, 63, 64.5, 66, 67.5, 69, 70.5 dB SPL), and found that while discrimination was generally poorer, absolute identification was equivalent for both age groups. Our results thus replicate Murphy et al’s findings, and suggest that auditory channel capacity is not affected by normal aging even when the ability to discriminate two closely spaced intensities is.