Happy July, everyone! As any American knows, Independence day is just around the corner. In Virginia and North Carolina, fireworks are allowed to be set off by professionals. Virginia allows non-projectile fireworks such as sparklers, and North Carolina allows a bit more.
Whats funny to me is that the law itself, per the American Pyrotechnics Association (for Virginia), had nothing regarding noise requirements. It turns out many jurisdictions have rules regarding the time of day fireworks can be set off for noise ordinance purposes. That being said, many commercial shows fall outside of those requirements anyway, and professional fireworks can easily fall into the 150dB range. At the point of explosion, this can be louder than many small caliber firearms.
Furthermore, firework volumes can vary wildly in relation to things like heat and humidity. Firework noise would probably sound louder in the humidity of Miami than the dry heat of Las Vegas.
Do fireworks have to be so loud? Well, no. There are a few companies out there who specialize in "quiet fireworks". In fact, quiet fireworks have accompanied loud fireworks in traditional shows for years, such as "Flying Fish" fireworks, which have a small wiggling tail, and a glittering burst, and have been used for years to accompany larger displays. The difference between the release of fireworks that are quiet and loud have to do with its chemistry. Loud fireworks have large, bursting explosions, and quiet fireworks have more color but less volume.
In fact, our own hearing isn't the only reason to keep fireworks quiet. In 2011, a small town in Arkansas was "rained on" by several thousand blackbird carcasses after a New Years Eve fireworks show. The prevailing theory was that the noise either startled them to death, or caused them to run into buildings out of a fear reaction from the noise. It certainly wouldn't be surprised, as I'm regularly comforting my terrified cats every July.
Defenders of pyrotechnic noise often claim that the loud ending provides the traditional crescendo that is associated with the show.
At the end of the day, no one, not even the makers of the fireworks, really know the noise rating of the fireworks show they are preparing. It is up to the viewer to apply appropriate hearing protection. In general, the viewing location of a fireworks show ***SHOULD*** have a noise rating around or below 120dB. Subtract the NRR rating from 120 to get your exposure. 97 dB is the volume that is safe for thirty minutes of exposure, the approximate length of a firework show. Please remember that children's ears are more sensitive than adults!
And enjoy your independence day!!!
