Objective: To explore the difference of the threshold of auditory steady-state evoked responses (ASSR) in awake and sleeping.
Method: Fifteen adults (30 ears) with normal hearing were selected to ASSR test. ASSR parameters: carrier frequency (CM)are 0.5, 1.0, 2.0, 3.0, 4.0, 6.0 kHz, modulation frequency (FM) are 46.81 Hz. The test was performed in two different status (in awake and sleeping).
Result: In awake, the thresholds of ASSR with FM of 46 Hz are significantly lower than 81 Hz (P < 0.01); In sleeping, the thresholds of ASSR with FM of 81 Hz are lower than 46 Hz above 2 kHz CM (P < 0.05), which thresholds were close to pure tone.
Conclusion: To select low modulate (46 Hz) frequency in awake, and use high modulate (81 Hz) frequency in sleeping. When perform ASSR test, the test values are closer to the actual hearing threshold.