Sound quality (6)
'sound quality' is the definition.
(I've seen this before)
This is all the 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 in another clue)
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" .)
'sound quality?' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for health that I've seen before include "Fit condition" , "It's said to be more than wealth" , "State of being free from illness" , "Physical welfare" , "10 18's great creation" .)
'sound quality?' is the definition.
(I've seen this before)
This is the entire clue.
(Another definition for validity that I've seen is " sound quality".)