modulation vs inflection

modulation and inflection both are nouns.

Word	Noun	Adjective	Verb	Adverb
modulation	Yes	No	No	No
inflection	Yes	No	No	No

As nouns, inflection is a hypernym of modulation; that is, inflection is a word with a broader meaning than modulation:

Other hypernyms of modulation include prosody.

As nouns, modulation and inflection are synonyms defined as:

modulation and inflection: a manner of speaking in which the loudness or pitch or tone of the voice is modified

modulation (noun)	inflection (noun)
the act of modifying or adjusting according to due measure and proportion (as with regard to artistic effect)	the patterns of stress and intonation in a language
(electronics) the transmission of a signal by using it to vary a carrier wave; changing the carrier's amplitude or frequency or phase	a manner of speaking in which the loudness or pitch or tone of the voice is modified
a musical passage moving from one key to another	deviation from a straight or normal course
rise and fall of the voice pitch	a change in the form of a word (usually by adding a suffix) to indicate a change in its grammatical function
a manner of speaking in which the loudness or pitch or tone of the voice is modified