TANNOY

[noun] [C] [UK] [trademark] - a system of equipment which is used for making speech loud enough for a large number of people to hear, esp. in order to give informationI missed my train because I couldn't hear what was given out over the Tannoy.We couldn't hear the announcement that was made on the tannoy system.Vans with tannoys fixed to them were driving around the streets, urging people to go and vote.