Reflected sound (4)
I believe the answer is:
echo
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">reflected sound</span>' is the definition.<br/ ><span class="explanation-format__explanation">(an echo is a reflected sound)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for echo that I've seen before include "Repeated sound" , "Be suggestive of" , "Before foxtrot" , "In Roman mythology, the nymph who loved Narcissus" , "Resound; (radar) return" .)