Were they scientific? They were!
I mentioned before here about Laguna Seca having a sound meter. If you’re louder than 92db (measured at 50' away on the right at turn 5) and can’t keep your car under that you get black flagged and sent home. So what do you do if you have a loud car?
The corvette is 96db when I start it if you’re measuring from right outside the car.
So I have slip on muffler tips to redirect the sound away from the meter.
I ran three tests. I had a very patient woman measure sound from 50' on a closed runway and went past as redline a few times.
I was good with nothing at all, reading 91db. However turn 5 is also a hill so that bit of load might erase that margin.
With the tips I got down to 87.9db. That works!
Then I went the extra mile and stuffed in some fireproof muffler packing used for motorcycles and put some mesh in to hold it and the bolt that holds the tips on held that too.
81db! 81! Bam!