Wind Turbine Noise Impact 

Wind Turbine Noise Impact - The noises generated by a wind turbine may be tonal, broad band, low frequency or impulsive.
Tonal noises have discrete frequencies whereas the broad band noises have continuous frequency above a level of 100 Hz.
The turbine may also produce noises with low frequency ranging from 20-100 Hz along with those due to momentary acoustic impulses. Much more on this topic, including describing WT mechanical noise, Aerodynamic noise and Turbine Tip Speed are explained in this video by Koby Plaschkes.