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2 April 2015 Last updated at 14:09 BST
Bluey, 12, came to Cambridge's Blue Cross on 9 March after her elderly owner was hospitalised.
Her constant purring which "sounds like a tractor" was putting off potential owners, staff said.
Centre manger Alan Maskell said: "A man who came to see her on Saturday just said, 'Oh no, that's much too loud'."
A member of staff who used a phone app to measure Bluey's purr said it registered at 93dB, which, if accurate, is about four times louder than a typical purr.
A woman who saw the charity's film was not put off by the noise and adopted the cat on Wednesday. Bluey will go to her new home on Friday.
A homeless cat shunned because it has "possibly the loudest purr in the world" has found a new home after the rescue centre released a film of it.