Family beginning to generate loud noise (5)
I believe the answer is:
clang
'loud noise' is the definition.
(loud metallic noise)
'family beginning to generate' is the wordplay.
'family' becomes 'clan' (I've seen this in other clues).
'beginning to' indicates taking the first letters.
The initial letter of 'generate' is 'g'.
'clan'+'g'='CLANG'
(Other definitions for clang that I've seen before include "Resounding effect" , "Make a loud metallic noise" , "Ring like a bell" , "Toll of a bell" , "Noise as of cymbals" .)