Auditory phase-synchronization near 40Hz is reportedly related to sensory stimulation. This study applied the phase synchrony analysis and Bi-coherence analyses to analyze the electroencephalographic measurements. Four experimental stages were conducted with 34 healthy high school students to collect the data: (A) resting with eyes closed, (B) listening to the classical music, (C) resting with eyes closed, and (D) listening to popular music. The result shows that the whole brain phase-synchronization occurs at 40Hz and lasts about 400 ms, which is quite different from the estimated 40Hz phase-coupling lasting about 20-25 ms in previous studies and seems to play an important role in inducing auditory attention loss. Additionally, the result also shows that hypersynchronous states may affect perceptual processing. This study develops an original nonlinear time serial analytical approach and suggests that 40Hz phase-synchronization might be an important indicator in perceptual process.