Abstract: A device (1) for insertion into an ear canal of a mammalian subject. The device includes a body (2) having a sound path extending therethough and a tensioned membrane (10) in the sound path. The tensioned membrane has at least one corrugation (12). The device further includes an adjustable member (6) arranged to bear against the membrane to adjust the tension of the membrane and thereby to alter an acoustic response of the sound path. The adjustable member may include a compressible portion (8).

Abstract: A device (1) for insertion into an ear canal of a mammalian subject. The device includes a body (2) having a sound path extending therethough and a tensioned membrane (10) in the sound path. The tensioned membrane has at least one corrugation (12). The device further includes an adjustable member (6) arranged to bear against the membrane to adjust the tension of the membrane and thereby to alter an acoustic response of the sound path. The adjustable member may include a compressible portion (8).

Abstract: A device for insertion into an ear canal of a mammalian subject, including a body, a first adjustable acousto-mechanical portion, a second adjustable acousto-mechanical portion and an adjustment arrangement. The body has at least one sound path extending therethrough. The first adjustable acousto-mechanical portion incudes an adjustable channel forming at least part of the sound path, and the second adjustable acousto-mechanical portion includes an adjustable membrane. The second adjustable acouto-mechanical portion is arranged acoustically in series with the first adjustable acousto-mechanical portion. The adjustment arrangement is configured for simultaneously adjusting the first and second adjustable acousto-mechanical portions to alter an acoustic response of the at least one sound path.