Effects of aging on the absolute pitch judgment and frequency following responses of electroencephalograms

Abstract

Absolute pitch (AP) possessors can name the pitch class of the note simply by hearing a periodic tone. It has been reported that the AP judgment can shift by one or two semitones when AP possessor become old. We confirmed this age-related AP shift by a series of psychophysical experiments with piano sounds as well as synthesized complex tones. AP possessors whose ages ranged from 20s to 50s participated in the experiments. The results showed that the aged participants were likely to assign the higher pitch classes than young participants for the piano sounds. Similar tendencies were observed for the synthesized, complex sounds if they contained lower order harmonics. The hearing levels, OAEs, and the frequency following responses (FFRs) of the EEG were also measured for the same participants. The hearing levels and OAE levels which could be indices in the cochlear mechanical properties could not explain the age-related AP shift. The phase locking values of the FFRs obtained at 98 and 220 Hz could neither be a good predictor of the AP shift. Although no plausible model to predict it exists, the age-related AP shift might bring another route of overlooked hearing problems.