Otoacoustic Emissions (OAEs)

Otoacoustic emissions (OAEs) are sounds produced by the inner ear when it is stimulated by sound. They are a type of spontaneous emission, meaning that they occur without any external stimulus. OAEs can be measured using a small probe that is placed in the ear canal.

What do OAEs measure?

OAEs measure the function of the outer hair cells in the cochlea. The outer hair cells are responsible for amplifying sound waves and sending them to the brain. If the outer hair cells are not working properly, OAEs will be absent or reduced.

What are the different types of OAEs?

There are two main types of OAEs:

  • Transient evoked otoacoustic emissions (TEOAEs): These are OAEs that are triggered by a brief sound stimulus.
  • Distortion product otoacoustic emissions (DPOAEs): These are OAEs that are created when two different frequencies of sound are presented simultaneously.

What is the normal range for OAE?

The normal range for OAE varies depending on the age of the individual and the type of OAE being measured. However, in general, OAEs should be present in both ears in people with normal hearing.

Why do we typically see normal OAEs in patients with ANSD?

ANSD stands for auditory neuropathy spectrum disorder. ANSD is a type of hearing loss that is caused by damage to the auditory nerve. The auditory nerve is responsible for sending sound signals from the inner ear to the brain. In people with ANSD, the outer hair cells are usually not damaged, so OAEs may be present even though the person has hearing loss.

Uses of OAEs

OAEs are used for a variety of purposes, including:

  • Hearing screening: OAEs can be used to screen for hearing loss in infants and young children.
  • Diagnosis of hearing loss: OAEs can be used to help diagnose the type and severity of hearing loss.
  • Monitoring of hearing loss: OAEs can be used to monitor the progression of hearing loss over time.
  • Research: OAEs are used in research to study the function of the inner ear.

Conclusion

OAEs are a valuable tool for assessing the function of the inner ear. They are a non-invasive and painless test that can be used to screen for hearing loss, diagnose the type and severity of hearing loss, and monitor the progression of hearing loss over time.

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