high pitch humming through air breather coming up into the intake

What is your question?

I have a 2002 Mercury Cougar and it has a high pitch humming through the air breather coming up into the intake and I can't figure out what's causing the high pitch humming. any thoughts on where it's coming from? what ever it is it won't let the car start and when it does start it keeps dying and it won't accelerate.

What makes this problem better or worse?

put carb cleaner in it and the humming got louder

How long has your 2002 Mercury Cougar had this problem?

2 weeks