Overall, beyond approximately 1km from the wind turbines a typical average nighttime A-weighted ambient SPL of 44.9dB was found, independent of the calculated WTN SPL (corresponding to 8m/s wind speed). An exception occurred within approximately 1km of the wind turbines for the 743 dwellings where calculated WTN SPL was above 35dB A-weighted. At these locations the average calculated ambient SPL dropped 0.6dB for every dB increase in calculated WTN SPL