In the classroom, the instructor s voice is competing with background noise, room echo, and distance. Therefore, the intelligibility of the instructor s voice is degraded by the poor room acoustics as well as the hearing loss. By placing the microphone close to the instructor s mouth, ALDs can provide clear sound over distances, eliminate echoes, and reduce surrounding noises. Assistive Listening Devices have proven to be an effective teaching tool for students with hearing loss. Providing a good listening environment can have a major impact on an individual s academic performance.
ALDs utilize different technologies.
Typically, they are wireless or wired. Wireless ALDs make use of radio frequencies, light rays, or magnetic inductive energy to transmit sound. Hardwired ones use direct electrical connection to transmit the auditory signal. Each system has special features, capabilities, advantages, and disadvantages. FM, Soundfield Amplification, and Induction Loop Systems will be discussed.