Anyone on Moparts own
one of the precision noise sources to calibrate dBA sound level meters,
or a recently calibrated meter?

I am looking for someone to measure the sound level of some Chrysler horn at a set distance away
so I can use it to do a rough calibration.

Looking online I have seen that locomotive horns have a dBA sound level standard from 100 feet away,
and aftermarket horn manufacturers give specs

https://www.law.cornell.edu/cfr/text/49/229.129

https://autoquarterly.com/best-loud-car-horns/

https://www.chem.purdue.edu/chemsafety/Training/PPETrain/dblevels.htm

I am trying to roughly check the accuracy of the free noise app for iPad/iPhone from the National Institute for Occupational Safety and Health.

https://www.cdc.gov/niosh/topics/noise/app.html

Do some of the automobile magazines routinely measure vehicle interior noise levels?