The most common and most likely answer to this crossword clue is the 4 letter word TONE
I've seen this crossword clue in The Daily Telegraph
T
O
N
E
More clues leading to the result TONE
- Sound quality coming from south west?
- Pitch in the direction of Geordieland?
- Weight nag shed creating bodily firmness
- Character to eviscerate Nazarene
- Accent found in public school, from first to last
- United on team’s original pitch
- Character is gem but no saint
- Turned round holding single from Parisian showing little appreciation of music
- Books about Geordie accent
- Initially type of noise emitting air
Buddy explains!

The straight part
We know that "Quality of sound" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case quality of sound = tone.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does TONE mean?
TONE noun- A specific pitch.
- (in the diatonic scale) An interval of a major second.
- (in a Gregorian chant) A recitational melody.
- The character of a sound, especially the timbre of an instrument or voice.
- General character, mood, or trend.
- The pitch of a word that distinguishes a difference in meaning, for example in Chinese.
- A whining style of speaking; a kind of mournful or artificial strain of voice; an affected speaking with a measured rhythm and a regular rise and fall of the voice.
- The manner in which speech or writing is expressed.
- State of mind; temper; mood.
- The shade or quality of a colour.
- The favourable effect of a picture produced by the combination of light and shade, or of colours.
- The definition and firmness of a muscle or organ; see also: tonus.
- The state of a living body or of any of its organs or parts in which the functions are healthy and performed with due vigor.
- Normal tension or responsiveness to stimuli.
- A gun
- To give a particular tone to
- To change the colour of
- To make (something) firmer
- To harmonize, especially in colour
- To utter with an affected tone.
- The one (of two)