In order to get my infant daughter to sleep, we would stand in front of the stove/oven vent fan. The white noise from the fan really seemed to make a difference.
Since standing in the kitchen all night long wasn't really an option, we got one of these white noise machines about eight years ago.
It's been running every night since we bought it. I bet I paid more than today's $31 sale price, but it has been worth its weight in gold.