Need help on this funny sound.

Can you blazer brothers or sisters give me a hand on this one? When I first start the car up and press the brake I hear this "whooshing" sound right behind my dash near the steering wheel. The brakes work well and the sound softens once I'm on the road, but this sound is weird...like rushing air or something. Is something about to blow so to speak. Thanks t :uhoh: o all for any help.

Sounds like the vac booster creating a vacume.

sounds normal to me, pressing the brakes is not a silent thing.

The noise is the booster working properly.