I had a Nikon F4 here for a few days. In fact, the sound is much less annoying than I had expected...
But I must admit, an F4 is not for me: too many buttons, even if I do not attach the MF-23 back. Is that a camera or a piano keyboard? It's in my list of trades now.
To me the most silent Nikon was the F2 Photomic I had burgled from my house when I was at work about twenty five years ago, I've never heard a peep from it since .