A sound-limiting device is provided, that includes an earplug body of aresilient elastomeric material, and that has a first portion whose shapecorrespondsgenerally to the shape of the vertical canal of a dog's inner ear, and asecond portionsized and configured to flex through the elbow region of the dog's inner earand into thehorizontal canal. A spring element can be encapsulated in the first portion ofthe earplugbody, and configured to apply a spring bias radially outward from an axisextending alength of the earplug body. The spring element is of a shape memory alloyhaving atransition temperature that is below a normal body temperature of a dog. Thedevice canalso include a sound conditioning element configured to produce a signal thatis audibleto an animal wearing the device.
