Crossword Genius

With which to sound alarm or ring the changes (6)

Ross

I believe the answer is:

hooter

I'm a little stuck... Click here to teach me more about this clue!

'with which to sound alarm' is the definition.
I can't judge whether this defines the answer.

'or ring the changes' is the wordplay.
'ring' becomes 'O' (letter resembling a ring).
'changes' indicates an anagram.
'or'+'o'+'the'='orothe'
'orothe' with letters rearranged gives 'HOOTER'.

Can you help me to learn more?

(Other definitions for hooter that I've seen before include "it smells" , "Factory siren" , "Siren, horn; nose" , "Car horn or slang nose" , "Gnomon" .)

I've seen this clue in The Times.
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