Audio device with pressure equalization

An audio device, comprising:

• an enclosure defining a sealed internal volume and including a first opening formed on a first surface and a second opening formed on a second surface;
• an acoustic transducer comprising a diaphragm and a magnetic motor assembly having a motor vent extending therethrough, the acoustic transducer being secured to the first opening such that the diaphragm is exposed through the first opening;
• and
• a semi-permeable membrane assembly;
• wherein a ventilation structure is defined by at least the motor vent and the second opening to establish gas communication between the sealed internal volume and an exterior of the enclosure, and the semi-permeable membrane assembly is positioned to traverse a gas outlet of the ventilation structure and is configured to permit gas exchange for pressure equalization while substantially blocking ingress of liquid and contaminants.