phoneme vs speech sound

phoneme and speech sound both are nouns.

Word	Noun	Adjective	Verb	Adverb
phoneme	Yes	No	No	No
speech sound	Yes	No	No	No

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

phoneme: (linguistics) one of a small set of speech sounds that are distinguished by the speakers of a particular language
speech sound: (phonetics) an individual sound unit of speech without concern as to whether or not it is a phoneme of some language

Other hypernyms of phoneme include phone, sound.

phoneme (noun)	speech sound (noun)
(linguistics) one of a small set of speech sounds that are distinguished by the speakers of a particular language	(phonetics) an individual sound unit of speech without concern as to whether or not it is a phoneme of some language