You can run a quiet fan, or buy “noise machines” from a baby store.  Or, for a buck or two, you can download an hour-long “white noise” track, burn it to a CD or mp3 player, and play on “repeat” to help soothe your baby (or yourself for that matter!) to sleep.  Click on the links below:

Try this one for simple, monotonous white noise.
Or check out one of these for something slightly less monotonous.
Finally, here is a website with several free white-noise downloads.

–  David Epstein, MD