Easy answer:
They’re not.
You are silly for thinking so.
Okay, okay. I’ll give a real answer.
First of all, my first answer is technically true. The commercials are not any louder than the TV show you’re watching, or at least they’re not any louder than the the loudest part of the show.
TV programs have a certain volume they’re allowed to hit. The whole show isn’t that loud though, otherwise all the actors would always be shouting at each other and a cat meowing be just as loud as a garbage truck being dropped off the empire state building. Instead TV shows opt to keep the volume at a nice, normal level until something loud happens like a bomb going off. By keeping the volume low most of the time, it’ll make the loud moments seem, well, louder.
Commercials, on the other hand don’t care about exposition. Their goal is to get your attention. So that commercial for hoveround will be just as loud as it possibly to get your attention. In the case of hoveround it’ll make sense to be loud since their target consumer is over 110 and most likely hard of hearing. The Toaster Strudels ad, on the other hand, is just loud because Pillsbury is being a douche.
If you are lucky enough to be watching your programs through a surround sound system, you may notice some advertisers will use every speaker to have their announcer shout at you. It’s annoying and why Thomas Edison invented the DVR.
If you absolutely positive that a commercial is way too loud, you can report it to the FCC. They are responsible for enforcing the “Stop my TV from yelling at me” rule. Maybe they’ll find out that Chex Mix ad really is too loud and will fine them a couple of bucks.
