modulation has 4 distinct synonyms spread across 3 of its 5 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. WordNet records no antonym for it — antonymy is a relation between word forms rather than concepts, so it is deliberately sparse.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
(electronics) the transmission of a signal by using it to vary a carrier wave; changing the carrier's amplitude or frequency or phase
Synonyms, antonyms and the broader and narrower relations for modulation come from Princeton University’s WordNet. Full sources and licences.
a manner of speaking in which the loudness or pitch or tone of the voice is modified
the act of modifying or adjusting according to due measure and proportion (as with regard to artistic effect)