Sound signals are a type of communication that uses sound waves to transmit information. AUDIO is a five-letter word that is used to describe sound signals. AUDIO is the term used to refer to any sound that is produced by a device or transmitted through an electronic medium. AUDIO can be used for a variety of purposes, such as broadcasting music, transmitting speech, and providing sound effects in movies. AUDIO signals can also be used to send messages over long distances, such as in radio and television broadcasts.