Sounds of awe (4)
'sounds of awe' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for oohs that I've seen before include "Exclamations of surprise, shoo away" , "With aahs, they're expressions of delight" .)
(Other definitions for gasps that I've seen before include "Draws breath sharply" , "'Pants, puffs (5)'" .)