Contributor to shorten a bleeped sound (7)
I believe the answer is:
tenable
'sound' is the definition.
(both can mean solid or viable)
'contributor to shorten a bleeped' is the wordplay.
'contributor to' says the answer is hidden in the clue (the letters of the answer contribute to the clue).
'TENABLE' is hidden within 'shorten a bleeped'.
(Other definitions for tenable that I've seen before include "Based on sound reasoning or evidence" , "Of argument, rational and defensible" , "Can be maintained" , "Late Ben (anag.)" , "Able to be believed" .)