The Cap Times – Craig Eley | guest columnist, Sep 28, 2019
[Our note: this may help people better understand the concern over the noise levels and why we believe it’s not just an “inconvenience.”]
“Many media outlets have used analogies to compare the decibel levels of the F-35 noise models in the Air Force’s draft environmental impact statement with everyday items, especially vacuum cleaners. However, these comparisons misrepresent both the methodology of the EIS and what makes humans perceive certain sounds as “noise.”…
For starters, the EIS noise maps are based on a measurement called “DNL,” or Day-Night Average Sound Level. This is an average of sound energy (measured in decibels) spread out uniformly over a 24-hour period. In order to average 65 decibels over the course of an entire day and night, you have to have events that are much, much louder — in some cases up to or in excess of 100 decibels. For example, the EIS notes that Ridgeway Church would experience sounds as loud as 107 decibels over five times per week. To translate that to an average of a 65-decibel DNL, community members would have to be running their hypothetical vacuums for 24 hours a day, seven days a week.
But even that does not paint an accurate picture of how loud these jets will be. Decibels themselves — and especially average decibels over time — are a terrible metric for understanding how humans actually perceive noise. The decibel is simply a measure of pressure change, or volume, but loudness is not the only factor that contributes to what most people think of as “noise.” Sounds that are regular and mechanical are much easier to get accustomed to, while sounds that are sharp and happen over short durations are much more likely to startle us and trigger the stress responses that make noise harmful to our whole bodies, not just our eardrums.
The sound of the F-35, in actual experience, will be more like someone sneaking up behind you with many vacuum cleaners and turning them all on once when you least expect it.”
READ THE FULL ARTICLE HERE