Tympanum (7)
I believe the answer is:
eardrum
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">tympanum</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that tympanum can be written as eardrum)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for eardrum that I've seen before include "Vibrating membrane in the head" , "Otic membrane" , "Listener partly" , "Aural membrane" , "Tympanum" .)