The study of otoacoustic emissions or OAS

The ear would not only perceive sounds, she also produced. A statement that awakens all our curiosity about the functioning of the hearing. But how is it? Is this normal? Zoom on the OAS.
Description and idnications

The oto-acoustic emission is all ears sounds in response to brief auditory stimuli from outside.

The mechanism of the OAS

During sound stimulation, the waves are transmitted from the pavilion to the eardrum and ossicles, through the external auditory canal. Then, the sound vibrations, resulting in movement of the ossicles are transmitted at auditory sensory pathways present in the cochlea.

At the level of the cochlea, hair cells exist, which, under the action of sound waves produce vibrations and contractions, generating very low sounds. These are the OAS.

There are:

- Spontaneous OAS

- The OAS caused transient

These OAS are seen from the external auditory canal by a recording device. The characteristics of the OAS may be affected by taking ototoxic drugs and the existence of a cold or ear infection.

Registration AEO is a painless and non-hazardous test. It is mainly practiced in the ear examinations of newborns in the hearing screening (suspected in the presence of a hereditary disease, for example).

But the review is also indicated in the hearing screening in adults, in case of:

- Prolonged and frequent exposure to loud noises or sounds that can cause acoustic trauma

- Extended Taking ototoxic drugs

How is the recording of OAS?

Registration mainly concerns OAS caused transient. The examination is carried out from the introduction of a small flexible tube, equipped with microphone in the ear canal. Sound stimulation is sent out, causing the production of OAS caused.

The small probe is connected to a device which translates the information sensed by the probe in a curve.