Sensorineural Hearing Loss

Some History

Types of Hearing Loss

Hearing loss is broken into two main categories:

• Conductive hearing loss means the hearing loss has something to do with the outer or middle ear (the pinna, ear canal, ear drum, middle ear bones, and middle ear space)

• Sensorineural hearing loss means the hearing loss is related to the inner ear (cochlea) or auditory nerve

  • Our cochleas are lined with thousands of hair cells that are tuned for individual frequencies, when we hear the frequency these hair cells are activated and send a signal to the brain

  • With sensorineural hearing loss, something has happened to bend or break these hair cells and a louder sound is needed to activate them as a result

Sensorineural Hearing Loss

Sensorineural hearing loss is the type of hearing loss that results from noise exposure in most cases, though conductive hearing loss can result from intense acoustic trauma that can disrupt the eardrum or middle ear bones

• In most cases with long-term noise exposure, notches are seen in the hearing test from 3000-6000 Hz as this is where our ear canals resonate and this part of the inner ear gets hit the hardest with noise exposure

• As we age, it is most common to lose the hair cells at the highest frequencies - this sounds like a loss in speech clarity rather than a loss in volume

  • high-frequency information in English is consonant sounds - /s/ /sh/ /t/ , those sounds that make it really easy to mistake one word for another and then you’re asking for repetition

There is no treatment to bring back the hair cells at this point in time (though many teams are researching this) - right now the only treatment for sensorineural hearing loss is hearing aids, which amplify only the frequencies you are missing.