[n] electro-acoustic transducer that converts electrical signals into sounds loud enough to be heard at a distance
[n] someone who expresses in language; someone who talks (especially someone who delivers a public speech or someone especially garrulous); "the speaker at commencement"; "an utterer of useful maxims"
[n] the presiding officer of a deliberative assembly; "the leader of the majority party is the Speaker of the House of Representatives"