Empirical Formulas of Sound Absorption Coefficients and Spectrums of

new theory is put forward that the sound absorption principle of perforated panel is similar to imperforated plate. Sound is absorbed by the vibration of panel, while not the holes on them. Base of this description, the empirical formulas of sound absorption coefficients of perforated panel and imperforated plate (diaphragm) are obtained, i.e. the sound absorption coefficients are descend with the increase of resonance frequency linearly. In addition, sound absorption spectrum formulas of perforated panel and imperforated plate (diaphragm) have also been found, they can be 0.1 to the power of function of resonance frequency’s sequence number and bandwidth.