US Patent 11706561 Balanced armature receiver with liquid-resistant pressure relief vent

A balanced armature receiver includes a gas permeable barrier located on a portion of the receiver defining a back volume to provide barometric relief. The barrier can be located in a wall portion or diaphragm of the receiver to vent the back volume to an exterior of the receiver directly, via a front volume, or via a nozzle. The gas permeable barrier is impermeable to liquid infiltration and can be configured to influence the low frequency response of the receiver.