Why dBG, dBC, and dBA “hide” the true “dose” of infrasound below 10 Hz

This post first appeared on windturbinesyndrome.com

The actual level of infrasound in this figure at 1 Hz is above 90 dB. Measuring infrasound with dBG at 1 Hz gives a level of only 50 dB.  Thus 40 dB is “hidden.”  Forty dB is a huge amount of sound energy, which will not be heard at that level, but may be perceived.

The graph also demonstrates why dBA is useless at accurately measuring below 200Hz.  Measurement with dBC likewise fails to measure the true low frequency noise and infrasound level once you get below 100 Hz.

The figure below came from the following sources:

» Salt, A.N. and Kaltenbach, J.A. (2011). Infrasound from Wind Turbines Could Affect Humans. Bulletin of Science, Technology and Science. (Aug 2011). 296-302.  (Downloadable from here.  Scroll down to the fourth article.)

» Van den Berg, G. P. (2006). The sound of high winds: The effect of atmospheric stability on wind turbine sound and microphone noise.  PhD dissertation. University of Groningen, Netherlands.

dB graph

About stopthesethings

We are a group of citizens concerned about the rapid spread of industrial wind power generation installations across Australia.

Comments

  1. Reblogged this on pappasven and commented:
    This is what the wind people are trying to hide!

  2. I agree with you 1957chev it is a load of bull shit the wind industry is promoting about no noise efects to humans living next to industrial turbines.

  3. Leith Elder says:

    The actual level of infrasound in this figure at 1 Hz is above 90 dB. Measuring infrasound with dBG at 1 Hz gives a level of only 50 dB. Thus 40 dB is “hidden.” Forty dB is a huge amount of sound energy, which will not be heard at that level, but may be perceived.

  4. If the truth about this whole fiasco was known by everyone, this would not be happening. It is by keeping the majority of people, ignorant of the facts, that they can cram their nonsense down people’s throats. Green on the outside, bullsh__ brown on the inside….

Trackbacks

  1. […] The so called “work” done by AGL’s tame acoustic consultants on infra-sound also used filters and weightings to EXCLUDE the vast bulk of the sound energy produced by the fans in question – a standard industry game of acoustic “hide and not seek” – for details on the trick see our post here. […]

  2. […] Check out this video where crack neuro-physiologist Prof Alec Salt explains the difference. And the EPA used the same filters and weightings that remove from measurements the bulk of the sound energy produced in the low-frequency range – for details on that little wind industry trick – see this post. […]

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