Otoacoustic Emission

Otoacoustic emissions: fundamentals and medical applications

Otoacoustic emissions (OAE) is one of the methods of audiological assessment of hearing, based on the analysis of sound vibrations occurring inside the ear. OAE can be measured using highly sensitive microphones placed in the external auditory canal. This allows you to obtain information about the functioning of the auditory receptor, as well as detect the presence or absence of disturbances in the perception of sound information.

The main source of sound vibrations in OAE are active mechanical processes occurring in the organ of Corti. The outer hair cells of the cochlea actively move and increase their movements due to positive feedback. These movements are transmitted to the basilar membrane, causing backward traveling waves. These waves reach the foot plate of the stapes and set in motion the chain of auditory ossicles, the eardrum and the column of air in the external auditory canal. As a result of these processes, extremely weak sound vibrations arise, which can be recorded using a microphone.

OAE can be spontaneous or induced. Spontaneous OAE is recorded in the absence of sound stimulation, and evoked OAE occurs in response to sound stimulation. Evoked OAE can be further divided into several subtypes, depending on the type of sound stimulation.

OAE has found wide application in medicine, especially for diagnosing hearing in newborns and infants. It is a painless and safe procedure that can be performed by a doctor without special training. During the procedure, a probe is inserted into the external auditory canal, which contains a miniature telephone and a microphone. If an OAE is detected, broadband acoustic clicks are sent into the ear canal.

OAE is one of the most accurate hearing diagnostic methods, allowing to identify defects in the perception of sound information. It can also be used to monitor treatment and evaluate the effectiveness of hearing aids. Overall, it represents an important tool for audiologists and other healthcare professionals.