Intercom speaker and Speaker unit

Intercom speaker noun - The loudspeaker on an intercom or public address system.

Speaker unit and intercom speaker are semantically related. In some cases you can use "Speaker unit" instead a noun phrase "Intercom speaker".

Speaker unit noun - Electro-acoustic transducer that converts electrical signals into sounds loud enough to be heard at a distance.

Intercom speaker and speaker unit are semantically related. Sometimes you can replace phrase "Intercom speaker" with "Speaker unit", this phrases are similar.