speaker vs tannoy

speaker and tannoy both are nouns.

Word	Noun	Adjective	Verb	Adverb
speaker	Yes	No	No	No
tannoy	Yes	No	No	No

As nouns, tannoy is a hyponym of speaker; that is, tannoy is a word with a more specific, narrower meaning than speaker:

speaker: electro-acoustic transducer that converts electrical signals into sounds loud enough to be heard at a distance
tannoy: a loudspeaker

speaker (noun)	tannoy (noun)
electro-acoustic transducer that converts electrical signals into sounds loud enough to be heard at a distance	a loudspeaker
someone who expresses in language; someone who talks (especially someone who delivers a public speech or someone especially garrulous)