Cold air intake making noise?

While sitting at idle the cold air intake tube will start to make a noise, like blowing into a bottle, and pretty loud. If I give it gas it'll stop. I put my hand on the intake tube where the intake manifold temperature sensor is, and it vibrated pretty good when the (sucking?) noise started. I've changed the mass air flow sensor and the air filter. All the connections are tight but it's making this noise. I'm trying to get a video, but it doesn't always happen.