Tone quality (6)
I believe the answer is:
timbre
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">tone quality</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for timbre that I've seen before include "Quality of voice, sounds wooden" , "Quality of sound of the voice" , "Tone of voice - sounds wooden" , "Distinctive tone" , "The distinctive property of a voice" .)