Coiffeur hears driers breaking down (11)
I believe the answer is:
hairdresser
'coiffeur' is the definition.
(I've seen this before)
'hears driers breaking down' is the wordplay.
'breaking down' is an anagram indicator.
'hears'+'driers'='hearsdriers'
'hearsdriers' is an anagram of 'HAIRDRESSER'.
(Other definitions for hairdresser that I've seen before include "Coiffeur, coiffeuse" , "Lock smith?" , "Stylist" , "cutter?" .)