Hearing discordant noise, about couple of seconds (7)
I believe the answer is:
session
'hearing' is the definition.
(I've seen this before)
'discordant noise about couple of seconds' is the wordplay.
'discordant' is an anagram indicator.
'about' indicates putting letters inside.
'couple of seconds' becomes 'ss' (abbreviation for second times two).
'noise' is an anagram of 'seion'.
'seion' placed around 'ss' is 'SESSION'.
(Other definitions for session that I've seen before include "Time in legislature" , "Period during which a group meets" , "Studio recording period" , "Meeting, sitting, term" , "Period devoted to an activity" .)