Sound quality (4)
'sound quality' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for tone that I've seen before include "Sound signal on a telephone" , "Sound - style" , "Pitch or timbre" , "Musical sound; quality of hue" , "Quality or character of voice" .)
'sound quality' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for timbre that I've seen before include "Tone-colour" , "Characteristic quality of sound" , "Distinctive tone" , "Distinctive sound quality" , "Sound's character" .)