Abstract: A sprung attachment arm for sound attenuating devices intended to form part of a head stirrup or to be fitted to a protective helmet. The arm (2) is constructed so that one end thereof can be attached to a protective ear muff (4) in a manner to spring-press the ear muff against the head of the wearer. The arm (2) has a substantially straplike configuration along at least part of its length and a cross-section through the straplike part presents at least one part which functions as a sprung leg (5) which forms an angle with adjacent parts of the straplike part (2). The straplike part (2) will preferably include at least two mutually angled sprung legs (5). A sprung arm of this configuration will produce an abutment pressure which will vary only slightly in response to different head sizes.