Sound of amusement (8)
I believe the answer is:
laughter
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">sound of amusement</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for laughter that I've seen before include "Manifestation of mirth" , "Howling" , "It's said to be the best medicine" , "Hilarity" , "Sound of merriment" .)