From Longman Dictionary of Contemporary Englishloudspeakerloud‧speak‧er /ˌlaʊdˈspiːkə, ˈlaʊdˌspiːkə $ -ər/ noun [countable] 1 
TCBTCRa piece of equipment used to make sounds louderfrom/over/through a loudspeaker The voice over the loudspeaker (=using the loudspeaker) said the flight was delayed.2 TCa speaker(3)
TCBTCRa piece of equipment used to make sounds louderfrom/over/through a loudspeaker The voice over the loudspeaker (=using the loudspeaker) said the flight was delayed.2 TCa speaker(3)Examples from the Corpus
loudspeaker• Because treble frequencies are directional and bass frequencies are not, standing in front of a loudspeaker cabinet always gives a brighter sound.• So microphones and loudspeakers were installed.• Later that evening, however, loudspeaker vans cruised the town, announcing the election for Friday, the next day.• Similarly, there are few restrictions on temporary use of loudspeakers, such as when messages are blasted intermittently from mobile vans.• Broadcasting via a system of street loudspeakers the radio is on the air for three hours each Sunday.• But there are differences, the most obvious being the loudspeakers.• Only if the loudspeaker starts singing a new song will her soliciting start afresh.• Mimicking candidates who campaigned with loudspeakers, I went outside every day and gathered neighborhood children and made speeches.from/over/through a loudspeaker• It was then Gedanken realized that all along she had been hearing the voices of the beetles over a loudspeaker.• Devotional songs blared from a loudspeaker attached to a tree.• A novelty for the home crowd at reserve matches in 1924-25 was music from gramophone records broadcast through a loudspeaker.• His voice could be heard over a loudspeaker.• Everywhere you go to shop they have Christmas muzak playing from loudspeakers secreted about the premises.• Those who arrived late had to listen to the Archbishop's address relayed over loudspeakers placed around the market square.• That is, deafening row from loudspeakers in cars with their windows open.• A typical campaign consists of politicians repeatedly shouting their name, party affiliation, and other slogans through loudspeakers. 