Woosh, swish, thwack, yee yaw, churn…if you live next to a wind turbine you will notice the distinctive noises they make but can you ever describe it? These comic book words do but are inapprpriate to describe a very real noise. When the sound of a turbine becomes an annoyance and the noise becomes nuisance, comic book descriptions to describe unwanted sounds are inadequate. Trying to describe to the Environmental Health Officer why a neighbours' turbine was causing us trouble, talking of the woosh, the weesh and the twack of it reduced what is a very real problem to the absurd.
Speech therapists use spectrograms as a tool to show how we form words, while record industry producers use spectrograms when mastering sound recordings to understand what happens when sound frequencies combine. Every spoken word, instrument, machine or a neighbours wind turbine will produce specific sound frequencies that create an acoustic signature. Wikipedia describes a spectrogram as “a visual representation of the spectrum of frequencies in a sound or other signal as they vary with time or some other variable.”
Put a simpler way a spectrogram is a picture of what we hear: "a sound image"
The spectrograms illustrated on this site are specific to one type of wind turbine - The Endurance E-3120 Wind Turbine. By taking over 100 hours of recordings and producing spectrograms of the results the noise of the turbine can be seen: - the E3120 turbine produces recognisable tonal sound at three frequency bands. This is verified by the E3120 acoustic performance test report (HM: 2300/R1 6th April 2011) published by Hayes Mckenzie Partnership which investigates the narrow band spectra characteristics of the turbine. Tonal assessment studies by Hayes Mckenzie Partnership identifies tones for an Endurance E3120 wind turbine at 287.2 Hz, 955.2Hz & 2307.8Hz for wind speeds of 6m/s. Our spectrogram images not only confirm this but indicate that these tones are audible at many other wind speeds and weather conditions. If you have similar experiences and would like to make similar recordings/images read on..............