By Liz Dadson Saugeen Times
Acousticians made some more noise about sound in the final week of the Environmental Review Tribunal into the appeal against the Armow Wind development in Kincardine. Friday afternoon (Jan. 10), Robert O’Neal, an expert acoustician and witness for the approval holder, Samsung Pattern Armow Wind Ontario GP, gave testimony about wind turbine noise.
He said there are two sources of sound in the wind turbines: the mechanical sound from the nacelle; and the aerodynamic noise from the blades. The older design, called “downwind,” has been replaced by a newer design, called “upwind.” With the old design, air moves around the tower, said O’Neal. That has been eliminated with the new design.
He described low-frequency noise and infrasound, stating that the human ear can hear noise from 20-20,000 Hertz (Hz). Low-frequency is found at 20-200 Hz, and below 20 Hz is infrasound. O’Neal said that, at 10 Hz, infrasound would have to be at 97 decibels (dBA) to be audible, but at 100 Hz, low-frequency noise could be heard at 27 dBA. Read article