They are not objectionably loud. Loud, yes, but it isn't painful to start it in the garage. Many 450s I have heard running around are much harder on the ears.

This reminds me of that sticker from the 90s. "Loud Pipes Save Lives." That sticker was on a friends 250r Honda with aftermarket exhaust that didn't have a silencer core installed. That thing would make your ears bleed.