Frequency-dependent changes in absolute hearing threshold caused by perception of a previous sound

Abstract

This study investigated effects of a previous sound presentation at the absolute threshold of hearing. Changes in threshold were measured when a pure tone at 60dB SPL preceded a test tone in the contra- or ipsilateral ear. When the previous and test sounds both had the same frequency of 500Hz, threshold decreased approximately 2dB in the contralateral ear, and increased slightly in the ipsilateral ear. On the other hand, when the frequency of the previous sound differed from that of the test sound, the threshold was decreased slightly in the ipsilateral ear.