Assistive listening devices in many theaters and similar spaces use arrays of infrared LEDs to send sound to listeners' receivers. Light-emitting diodes (as well as semiconductor lasers) are used to send data over many types of fiber optic cable, from digital audio over TOSLINK cables to the very high bandwidth fiber links that form the Internet backbone. For some time, computers were commonly equipped with IrDA interfaces, which allowed them to send and receive data to nearby machines via infrared. COUNT 4
QSN1 Where are infrared LEDs used in everday life? ANS1 theaters QSN2 How are LEDs used in theaters? ANS2 to send sound to listeners' receivers QSN3 LEDs can send data over what type of cable? ANS3 fiber optic QSN4 What type of fiber forms the backbone of the internet? ANS4 very high bandwidth