1. Electronic equipment that converts sound into electrical signals that can be transmitted over distances and then converts received signals back into sounds Noun
2. (phonetics) an individual sound unit of speech without concern as to whether or not it is a phoneme of some language Noun
3. Electro-acoustic transducer for converting electric signals into sounds; it is held over or inserted into the ear Noun
4. Get or try to get into communication (with someone) by telephone Verb