Ear dominance effects in loudness following auditory adaptation

Abstract

In adaptation experiments, one factor which has not been reported is the possibility of differing effects depending upon whether the dominant ear or the nondominant ear received the stimulus. The present experiment utilized a monaural measurement technique which presented a 500-Hz pure tone to the experimental ear for 7 min of adaptation exposure at a 50 dB SPL. Ten subjects were adapted in the right ear and ten in the left ear. A 10 000-Hz tone was used as a comparison tone. There was a significant difference in right- versus left-ear adaptation (12.88 vs 4.20 dB) with a t of 3.8 and p less than 0.001. An experiment using binaurally presented stimuli with the adapting stimulus at 500 Hz and 60 dB SPL, while the comparison stimulus was also 10 000 Hz (as above) but presented to the opposite ear, yielded significant ear differences. The right and left ear yielded 5.0 and 6.0 dB, respectively, with t of 2.93 and p less than 0.05. Results of both studies would suggest that the ear used for adaptation does markedly affect the magnitude of loudness adaptation measured.