modulate vs speak

modulate and speak both are verbs.

Word	Noun	Adjective	Verb	Adverb
modulate	No	No	Yes	No
speak	No	No	Yes	No

As verbs, speak is a hypernym of modulate; that is, speak is a word with a broader meaning than modulate:

Other hypernyms of modulate include mouth, talk, utter, verbalise, verbalize.

modulate (verb)	speak (verb)
adjust the pitch, tone, or volume of	express in speech
fix or adjust the time, amount, degree, or rate of	exchange thoughts; talk with
vary the frequency, amplitude, phase, or other characteristic of (electromagnetic waves)	use language
vary the pitch of one's speech	give a speech to
change the key of, in music	make a characteristic or natural sound