Stimulus frequency OAE measurement using the suppression method

Abstract

Stimulus frequency otoacoustic emission (SFOAE) was measured in 5 healthy volunteers using the suppression method. In this method, the SFOAE suppression level was calculated as the difference between the sound levels of the external ear canal to the probe tone alone and to the probe tone along with the suppressor tone having a frequency close to the probe tone. For a probe tone of 4000 Hz and 50 dB SPL, the suppression level of SFOAE to a 70 dB SPL suppressor was maximum when the suppressor frequency was in the range from nearby to 1200Hz above the probe frequency. As the suppressor level decreased, the SFOAE suppression level also significantly decreased when the suppressor frequency was lower than the probe tone, but scarcely so when the suppressor frequency was higher than the probe tone. These results were similar to those of previous studies. Further clinical applications of SFOAE, in addition to the mechanism of SFOAE suppression, are discussed.