As a scuba diver descends toward the bottom of the ocean she experiences the sensation of her ears popping based on your observations from the can crush lab explain why this would happen

Release of pressure on equalizing the pressure

Explanation:

When a scuba diver descends into the sea, it becomes essentially important to equalize the underwater pressure and pressure inside the ear.  

The pressure increases with the depth therefore when a scuba diver go deep into the ocean she/she pushes the Eustachian tube to equalize the pressure. When an Eustachian tube is pushed towards the outward direction, more air is allowed to come in and balance out the external pressure in the middle ear thereby producing a popping noise.  

as many times as you want