Sliding door entrance filter

standing between two sets of sliding door under a big air conditioner. when the doors were closed, they tightly sealed the sounds from inside the store and from the street on the other side. you can only hear the isolated drone of the air conditioner. as soon as the doors slide open all kind of sounds gush into the small space. crying children, customers, cash registers, clutter of the shopping carts, barking dog, passing cars, steps.