These devices function as a small amplifier, and are the size of an MP4 or old transistor radio. Earphones are attached via an earphone jack and the volume is controlled manually. Such devices can be...

These devices function as a small amplifier, and are the size of an MP4 or old transistor radio. Earphones are attached via an earphone jack and the volume is controlled manually. Such devices can be used to communicate pertinent information to a patient and then can be removed for the comfort of the patient when not in use.