Effect of Sleepiness on Frequency Dependence of Auditory Response

Abstract

So far, we investigated the relationship between sleepiness and amplitude of amplitude-modulation following response (AMFR) to find the best tone for waking up a drowsy driver. In this study, we recorded AMFRs evoked by amplitude modulated (AM) tones. In this study, we used AM tone whose carrier frequencies (FC) were 250, 500, 1000, 4000, and 8000 Hz. Sleepiness level was divided into three states, low sleepiness, high sleepiness, and sleep states, by using a reaction time of vigilance task. We found that AMFR evoked by AM tones whose frequency was above 1000 Hz AM tone in high sleepiness and sleep states were small that in low sleepiness, but AMFR evoked by 250 and 500 Hz AM tone did not decrease during high drowsiness state. These results suggest that the low-frequency tone is suitable for drowsy drivers to wake up.