speech rhythm vs prosody

speech rhythm and prosody both are nouns.

Word	Noun	Adjective	Verb	Adverb
speech rhythm	Yes	No	No	No
prosody	Yes	No	No	No

As nouns, prosody is a hypernym of speech rhythm; that is, prosody is a word with a broader meaning than speech rhythm:

speech rhythm: the arrangement of spoken words alternating stressed and unstressed elements
prosody: the patterns of stress and intonation in a language

Other hypernyms of speech rhythm include guide, template, templet, inflection.

speech rhythm (noun)	prosody (noun)
the arrangement of spoken words alternating stressed and unstressed elements	the study of poetic meter and the art of versification
	the patterns of stress and intonation in a language
	(prosody) a system of versification