Futurama episode squeak

Okay, you can go ahead and think I'm crazy about this, but I'm not, I tells ya! Anyway...

I was just watching the (final) Futurama episode 'The Devil's Hands are Idle Playthings', the one with the opera. At the end, the holographic Fry and Leela walk off into the distance. And just as the credits appear, there's a squeak! I haven't heard this on any other episodes. The first few times, I was willing to ignore it, but it's been several dozen times now that I've heard it...What the heck is going on?

*And I don't necessarily need mocking in the answers I will hopefully receive for this question. Go ahead and tell me you don't hear it, but don't say I'm an idiot for hearing it.

Its subliminal messages.
Ha.
Dont worry its futurama its stupid!

so you heard a...squeak?
well if you believe in like ghosts and such well id probably b freaked out 2
id have to watch it tho to be on your side but just in case if it were like the devil or something id probably do some praying or something like that
but thn again there could b something wrong with the episode