Extremely loud (12)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">extremely loud</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 ear-splitting that I've seen before include "Painfully shrill" , "Deafening" , "Excessively loud" , "Extremely loud" , "Painfully loud" .)