Sty sound (4)
I believe the answer is:
oink
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">sty sound</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for oink that I've seen before include "Pig's noise" , "Porker's cry" , "What you get from pen" , "farmyard noise" , "Farmyard sound" .)