Acoustics 101

Noise is irritating and if at great enough levels harmful. To reduce the noise levels from machinery to operators or bystanders, noise control materials are commonly used. Noise control materials are engineered to reduce noise levels caused by airborne noise and structure borne noise. Airborne noise is direct transfer of noise in the air. Structure borne noise is the transfer of energy from vibrating surfaces into noise. Airborne noise can be absorbed or blocked. Noise control materials to absorb sound are called Sound Absorbers. Noise control materials to block sound are called Barriers. Structure borne noise is controlled by reducing vibrations. Vibrations can be reduced by materials that are isolators or damping. Vibrations transmitted from operating machinery to its mounting structure are reduced by vibration isolators. Vibrations of panels are reduced by damping.