Assistive listening systems (ALSs), sometimes called FM or DM systems, are small, discrete devices that increase the clarity of targeted sounds, like a speaker's voice, by simultaneously amplifying the target and eliminating extraneous noise. An ALS typically consists of a receiver, worn by the student, and a transmitter that includes a microphone). In some cases, the transmitter may need to be worn on a neck-loop or lapel-clip by the faculty member. Consult with the student for proper placement.