Indeed. You need to tell us what brand it is. My EF 50mm f/1.4 was ultra-quiet when focusing, until it met concrete and had to have the focus mechanism replaced. Now it's a little noisier than I'd like, but...meh.
Perhaps. Is it refurbished? Very odd that it would be noisy if it's new. (This is one of the reasons why I always insist on testing the lens before buying it. These puppies are expensive!)