sound structure vs morphology

sound structure and morphology both are nouns.

Word	Noun	Adjective	Verb	Adverb
sound structure	Yes	No	No	No
morphology	Yes	No	No	No

As nouns, sound structure and morphology are synonyms defined as:

sound structure and morphology: the admissible arrangement of sounds in words

Other synonyms of sound structure include syllable structure, word structure.

sound structure (noun)	morphology (noun)
the admissible arrangement of sounds in words	the branch of biology that deals with the structure of animals and plants
	studies of the rules for forming admissible words
	the admissible arrangement of sounds in words
	the branch of geology that studies the characteristics and configuration and evolution of rocks and land forms