It's not from Pac-Man. That's the sound effect from Super Mario Brothers when he eats a Power-up mushroom.
I actually like it, most of the fans do as well. The "Woot-Woot!" sound however is pretty much universally loathed, however.
I'll admit the new scoreboard is a bit much. It almost gets in the way of seeing the actual game. But, fans were demanding it, so we can't backtrack now and say "Well, we didn't know you'd go THAT big."
I kinda wish a team would buck the trend and go with an old-school screen.
It's possible though that these are just as cost-prohibitive as the new stuff.
As for the goal siren...I read the Avs were forced to change it from the Avalanche warning siren to that obnoxious bullhorn because the law prohibited the use of the sound or something like that. For what it's worth I can't stand it either.
Could be worse I guess...Columbus has a cannon.