[Observation on sleep improvement under noise environment by wearing earplugs]

Sleep experiments were done in 6 subjects under 3 conditions. (1) Quiet, background noise level lower than 45dB (A); (2) Noisy with earplugs, ambient noise level 90dB (A); (3) Noisy, ambient noise level 90dB (A), and subjects wearing earplugs. EEG, REM and EMG during sleep were recorded. Sleep latency, times and duration of waking up, sleep rate of each stage and total sleep rate were analyzed. It shows that sleep under noise condition can be improved by wearing earplugs.