The pounding noises when many get wrongly shut out (5)

'the pounding noises' is the definition.
The definition and answer can be both related to natural events as well as being plural nouns.
Maybe you can see an association between them that I can't see?

'many get wrongly shut out' is the wordplay.
I cannot quite understand how this works, but
'many' could be 'd' (Roman numeral for 500) and 'd' is present in the answer.
an anagram of 'shut' is 'thus' which is within the remaining letters.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).

'when' acts as a link.

Can you help me to learn more?