Pamphlet that's followed, so we hear (5)
I believe the answer is:
tract
'pamphlet' is the definition.
(I know that pamphlet can be written as tract)
'followed so we hear' is the wordplay.
'followed' becomes 'tracked' (to track is to follow or tail).
'so we hear' shows a homophone (sound like).
'tracked' sounds like 'TRACT'.
'that's' is the link.
(Other definitions for tract that I've seen before include "Pamphlet; area of land" , "lot of ground?" , "Extended area of land" , "Piece of writing" , "Lots of land" .)