Dial sound (4)
I believe the answer is:
tone
'dial sound' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for tone that I've seen before include "Vocal sound of note" , "Quality of sound, voice say" , "Musical sound; quality of hue" , "Musical note; general character" , "Theobald Wolf . . . ." .)