From Longman Dictionary of Contemporary Englishldoce_223_cmicrophonemi‧cro‧phone /ˈmaɪkrəfəʊn $ -foʊn/ ●●○ noun [countable] 
TCRa piece of equipment that you speak into to record your voice or make it louder when you are speaking or performing in public She spoke confidently into the microphone. They searched the room for hidden microphones.
TCRa piece of equipment that you speak into to record your voice or make it louder when you are speaking or performing in public She spoke confidently into the microphone. They searched the room for hidden microphones.Examples from the Corpus
microphone• Beldock takes her place behind a microphone during morning assembly and surveys 1,200 faces whose heritage spans six continents.• He was handed a microphone, but with an irony that summarised Labour's plight, it failed to work.• The user makes a local call to dial into the Internet, then talks into a microphone.• We shout our hatred of them at public forums and into radio and television microphones.• He sights a bird and aims the microphone in its direction.• In this case another usher or bridesmaid could take over the duty of checking the microphone.• She can allow speakers to overrun by 20 seconds before cutting off their microphone.• The idea of using two microphones appeals to me because it could stimulate two ears. 