The greatest effect of the noise is the number of false starts by the opponents’ offense - a statistic in which the Seahawks lead the league in their home games.
Yes, lead the league with 2.36 a game since the new stadium was completed, compared to a league average of around 1.5 per team per game. I don’t see that “extra” 1 5 yard penalty per game really changing things dramatically. Also interesting to note that while they do hold the record since 2005 for opposing false starts, they’re only 15 up on Minnesota in second place, and that includes the record 11 the Giants had there in one game. Throw that statistically aberrant game out of the mix and they’re only 4 up on Minnesota a team nobody really considers to have that great a home field advantage.