whispering dome vs whispering gallery

whispering dome and whispering gallery both are nouns.

Word	Noun	Adjective	Verb	Adverb
whispering dome	Yes	No	No	No
whispering gallery	Yes	No	No	No

As nouns, whispering dome and whispering gallery are synonyms defined as:

whispering dome and whispering gallery: a space beneath a dome or arch in which sounds produced at certain points are clearly audible at certain distant points

whispering dome (noun)	whispering gallery (noun)
a space beneath a dome or arch in which sounds produced at certain points are clearly audible at certain distant points	a space beneath a dome or arch in which sounds produced at certain points are clearly audible at certain distant points