Manage to follow street code with a listening device (11)
I believe the answer is:
stethoscope
'a listening device' is the definition.
(I've seen this before)
'manage to follow street code' is the wordplay.
'manage' becomes 'cope' ('cope' can be a synonym of 'manage').
'to follow' says to put letters next to each other.
'street' becomes 'st'.
'code' becomes 'ethos' (moral code).
'st'+'ethos'='stethos'
'cope' put after 'stethos' is 'STETHOSCOPE'.
'with' acts as a link.
(Other definitions for stethoscope that I've seen before include "Doctor's instrument" , "Medical instrument" , "Instrument used in listening" , "listening device" .)