When my first was born we found the hoover and washing machine really settled him to sleep. However, that didn't seem very eco friendly so we bought a white noise CD for about £3 off eBay - absolute lifesaver!! Both babies used it every night (and we're great sleepers) until were about 18 months, we then switched to story CDs which they still have now they are 7 and 9.
White noise to settle a newborn - Ask Norfolk Parents
White noise to settle a newborn