Larynx (5,3)
I believe the answer is:
voice box
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">larynx</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for voice box that I've seen before include "The informal larynx" , "Organ" .)