Can anyone recommend a loud bell?

[ISaySteadyOn]

DCat has a collar with a bell on and it used to be very loud. We could hear wherever she was. She wears it because we hoped it would help the birds hear her. However, she has figured out how to muffle it and we have found 2 dead birds. So does anyone know of any bells that prevent muffling or are just really loud? Thanks.

I'm not keen on collars for safety reasons and not sure they really make much difference, but friend's cat has falconry bells on his collar which make a lovely noise!

That's a good idea! Thank you.