Abstract: An ear defender for a headset, the ear defender comprising a rigid shell having holes in a central portion to permit the passage of ambient sound and including a valve mechanism to close the holes as required. The shell consists essentially of a unitary construction, being formed as a one-piece moulding. The valve mechanism consists of a fixed plate and sliding plate both of which have holes which can be aligned to open the valve or misaligned to close the valve. The valve is mounted wholly within the shell so providing protection for the valve mechanism. Access to the valve and to other components within the shell is thus provided entirely from one side of the shell.