Andrew, I'm not sure about the legality of doing that but if you consider the popular mod of liberating extra kilowasps by cutting holes in the factory airbox... more air, more fuel, more bad stuff burnt, more bad stuff out the exhaust... that's the logic I would apply. Isn't it also going to contribute to induction noise that might register on the dB test?
Having said that I hope I'm wrong! Just thinking out loud as usual.
