Patulous eustachian tube noise attenuator

This falls into the category of "orphan" medical conditions: one so rare, it's probably not worth any manufacturer's time to develop a solution.

A patulous eustachian tube is one that does not close properly. As a result, sufferers hear a roaring noise with every breath, driving them absolutely nuts. Some people undergo surgery, which sometimes helps but often not. No good solution exists.

If a hearing aid were to sense eardrum movement by light beam (for instance, time-of-flight of a light pulse or modulation of an interference pattern from coherent-light LEDs), its audio transducer could generate a counter pressure wave to stabilize the eardrum. (There would be some phase lag due to the time-of-flight of the pressure wave from hearing aid to eardrum, which would reduce the device's effectiveness at high frequencies -- wavelengths approximately 2x the distance from transducer to eardrum. I think. This is the HALF-bakery, right?)

A microphone on the outside of the hearing aid would pick up outside audio and transmit it through, using the same audio transducer. The signal from the inside would be subtracted from that audio, with the result being hearing free of internally generated noise.