In the racing world today, there are many racetracks throughout the country that are under siege from neighboring communities. These communities are trying to close down our race tracks because of noise pollution. It’s time that all of us in the racing community start becoming pro-active by policing ourselves when it comes to noise pollution.
What is “dBA”
When we say “dBA: we are referring to “A” weighted reading as read from a sound level meter.
A sound level meter measures sound pressure. The meter has a “weighting” switched such that the dB level shown on the meter can be switched to “A” weighted or “C” weighted.
“A” weighted readings are adjusted by the meter for the frequency (pitch) of the sound. “C” weighted readings are not adjusted.
The reason “A: weighted readings are adjusted lies in the fact that the human ear does not perceive the same sound pressure level at different frequencies as the same loudness. Specifically, a sound pressure level at low frequency is not perceived as loud as the same sound pressure level at higher frequencies. We might say that “dBA” is a measure of “loudness.
What sound levels are communities expecting:
- Tracks with limited noise issues are probably looking for dB reading of 100 dbA or less.
- Tracks with noise issues will be under 95 dBA
- California State Fairgrounds and may other States are 95dBA .
- Tracks in communities will be around 90 dBA to 95 dBA
When testing at your track:
- Meter should be set on “A” scale
- Meter should be 100 ft. from the sound source or race car.
- Testing should be done with one car on the track at a time. Multiple cars on the race at the same time will make the test read higher.
- Walls and bleachers may create a sound bounce thus giving you an inaccurate reading.