Is this noise normal?

Bought mine used with 10,000 miles. Love everything about it. When the car is first started it seems to run sort of strange. For about a minute it sounds almost as if there is an exhaust leak. It's pretty noisy. After that first minute it idles down and is nearly silent. As I did not purchase the car new, I wasn't sure if that was normal or how it sounded when new. Any idea?