Echo distorted the line (4)
I believe the answer is:
oche
'line' is the definition.
(I've seen this before)
'echo distorted' is the wordplay.
'distorted' is an anagram indicator.
'echo' anagrammed gives 'OCHE'.
'the' acts as a link.
(Other definitions for oche that I've seen before include "sporting line" , "Behind which a darts player must stand" , "Line not to be crossed" , "The mark at darts" , "What darts player stands behind" .)