In general, sound frequency of human sense of hearing is from 20Hz to 20 KHz including the human voice spectrum range 150Hz ~ 4 KHz, and various musical spectrums range 40Hz ~ 18 kHz. Distribution of average spectral energy is that bass and bass is maximum, mid-treble is secondly, and treble is the least, and the human voice energy is concentrated in frequency range of 200Hz ~ 3.5 KHz. Peak of these random signal amplitudes are higher than of its average value about 10 ~ 15dB.