The University of Southampton

Types of hearing loss

Sensorineural hearing loss occurs when there is a problem within the inner ear. The hair cells are missing or damaged. This means that they can no longer adequately convert sound into the electrical signals the brain needs to interpret sound.

When the damage is significant a person will be diagnosed with a severe to profound hearing loss. This means hearing aids can no longer make the sound clear because too many hair cells in the cochlea have been damaged or lost.

Understanding an Audiogram

When an Audiologist carries out a hearing test, they mark where the patient can just hear different pitches of sound on an audiogram (pictured below).  The further down the chart, the louder the sound has to be for the patient to hear it.

The different pitches tested are those that are important for us to hear speech information.  An audiogram goes from low pitched sounds (125 and 250Hz) on the left hand side to high pitch sounds (up to 8,000Hz) on the right.  The pink and grey area at the bottom of the chart shows severe to profound hearing loss.  In this situation a cochlear implant may be appropriate.

Image result for audiogram hearing loss


Key Concepts