Ha, okay, I guess it would've been uncharacteristically mean of Marvel to ensure their show is for teens only by including sfx that middle-aged people can't hear! And now that I think of it, I'm not sure that teens would get the full impact of a theme song from the 1990s, anyway.

I just watched the scene again on my computer instead of my "home theater" system, and the sound is completely 100% unmistakable. So I think I just have my living room speakers set up wrong!