With the theory of sound absorption by sympathetic vibration and attrition,we pad a layer of inorganic fiberplate in the cavity of the back of gypsum perforated plate,abatvoix will be made.With wider absorption frequency(100-5000Hz) and higher absorption coefficient(0.5-0.82),abatvoix is widely used in the ceiling of factory to reduce noise,decoration of upper structure and wall in broadcast & TV record,broadcast studio,hotel,theater,meeting hall,tesching building,computer room and so on ,It can adjust in door reverberation and avoid echo and increase tone.