Age-related changes in detecting a mistuned harmonic

The effects of age on discriminating simultaneous sounds were investigated by comparing the hearing threshold in detecting a mistuned harmonic in youn g, middle-aged, and older adults. The stimuli were complex sounds containin g multiple harmonics, one of which could be ''mistuned'' so that it was no longer an integer multiple of the fundamental. Older adults had higher thre sholds than middle-aged or young adults. The effect of age was greater for short than for long duration sounds and remained even after controlling for hearing sensitivity. The results are consistent with an age-related declin e in parsing simultaneous auditory events, which may contribute to the spee ch perception difficulties in the elderly. (C) 2001 Acoustical Society of A merica.