Does an extended period in a microgravity environment affect human hearing? Starting in 2002, Creare began work with NASA to design a hearing assessment system for astronauts working on the International Space Station (ISS) to answer this question.

In conjunction with Dartmouth-Hitchcock Medical Center, Creare combined two separate hearing tests: a Bekesy-like automated audiogram as well as a Distortion Product Otoacoustic Emissions (DPOAE) test, which measures subtle tones produced by the cochlea at the threshold of hearing. Flight specifications required that we miniaturize the hardware, so we used an ear probe with miniaturized microphone and speakers, and designed the microphone amplifier to fit onto an off-the-shelf sound card.

The size, portability, and integration of several tests in one compact system has led us to earthbound applications for hearing evaluation in the workplace, neonatal care, and testing and treatment in remote developing regions as well as for future microgravity testing opportunities.

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