274 Oto-Acoustic Emissions – Why this is a game-changing development in hearing conversation and a true and effective approach to health surveillance

The most vulnerable structure in our auditory system are the outer hair cells in our cochlear. These are first injured by loud sound and ototoxins. A significant percentage of these cells can be damaged before hearing loss becomes measurable on the traditional hearing test i.e. audiometry. With this ‘hidden’ damage we will have difficulties with our hearing without detection on an audiogram. As health conversation crusaders, we need to highlight any effect from damaging exposure quickly to prevent injury. OAE can detect damage at an early stage and so actions can be taken to improve control measures and prevent hearing loss. This approach also helps motivate the individual early on to protect their health. Audiometry is a behavioural test which was first developed in the 1800s. It is useful in measuring hearing loss. However, the point of a hearing conservation programme is to prevent hearing loss, not to measure it. Audiometry used in isolation as a test that measures hearing loss only gives a useful result when preventing hearing loss has failed. OAE compliments the audiogram. OAE has been used for over 30 years to test the hearing of new born babies. It is non-invasive, it does not require a soundproof room, and it is completely objective. It measures the function of the outer hair cells which will show at the very earliest opportunity evidence of reduced function of our inner ear before we lose our hearing. We can then be proactive and prevent hearing loss.