In quiet ways, they’re used by writers (4)
I believe the answer is:
pens
'writers' is the definition.
(I've seen this before)
'in quiet ways they're' is the wordplay.
'in' indicates putting letters inside.
'quiet' becomes 'p' (music symbol for 'piano').
'ways' becomes 'es' (east and south - two directions).
'they're' becomes 'n' (I can't explain this - if you can you should believe this answer much more).
'p'+'es'='pes'
'pes' placed around 'n' is 'PENS'.
'used by' is the link.
Can you help me to learn more?
(Other definitions for pens that I've seen before include "stalls" , "birds" , "Literary thought or reflection" , "Dashes off" , "Writing implements" .)