In Australia, detective, lawyer and egghead are loud enough to be heard (7)
I believe the answer is:
audible
'loud enough to be heard' is the definition.
(I've seen this before)
'in australia detective lawyer and egghead' is the wordplay.
'in australia detective' becomes 'audi' (I am not sure about this - if you are sure you should believe this answer much more).
'lawyer' becomes 'bl' (Bachelor of Law).
'and' says to put letters next to each other.
'egghead' becomes 'e' (head letter of 'egg').
'audi'+'bl'+'e'='AUDIBLE'
'are' acts as a link.
Can you help me to learn more?
(Other definitions for audible that I've seen before include "Able to be heard" , "Loud enough to be heard" , "Hearable" , "Within hearing range" , "Within earshot" .)