The mechanical properties of earmuffs

The physical properties of circum-aural hearing protectors, such as mass, clamping force and cup volume, have an influence on the attenuation performance of the device. This paper closely examines the physical and acoustic properties 39 of hearing protectors readily available to all users. The results indicate that attenuation increases with clamping force up to a limiting value of around 11 Newtons above which expected increases in attenuation are very small for large increases in clamping force. Likewise increasing the (newly introduced term) bulk of a hearing protector (volume, mass and cup elements) increases the attenuation but, as with clamping force a limit is reached where increased bulk increases discomfort and wearing difficulty.