Blog

01

Definition: Otoacoustic emission (Otoacoustic emission, OAE) is an audio energy produced in the cochlea that is released into the external auditory canal through the ossicular chain and the tympanic membrane. It reflects that the cochlea not only passively feels the sound signal, but also has the function of actively generating sound energy.

02

Classification: According to whether there is external stimulus signal, it is divided into:

Spontaneous otoacoustic emissionsSpontaneous otoacoustic emission, SOAE) refers to the acoustic signal recorded in the external auditory canal by the cochlea without any external stimuli.

Evoked otoacoustic emissionsEvoked otoacoustic emission, EOAE) refers to the release of acoustic energy produced by the cochlea under different external stimuli.

Induced otoacoustic emissions can be further divided into four categories: transient acoustically induced otoacoustic emissions (TEOAEDistortion product otoacoustic emission (DPOAE), stimulating frequency otoacoustic emissions (SFOAE), electrically induced otoacoustic emissions (EEOAE).

The two most common types of clinical use areDPOAE,TEOAE.

DPOAE: refers to an otoacoustic emission produced by two initial pure tone stimuli having a certain frequency ratio and a certain intensity ratio;

TEOAE: refers to the acoustic energy released by the cochlea after a transient stimulation and released in a certain form after a certain period of time. The form is determined by the characteristics of the stimuli.

03

Result interpretation:

DPOAE:

1, the reaction amplitude exceeds the noise floor3dBAnd above, ieSNR≥3dB;

2, detection rate ≥60%, that is, three or more of the five test frequencies are derived;

3,DP值≥ -10dB.

The above shows the passage (PASS), otherwise it failed (REFER）.

TEOAE:

1, the reaction amplitude exceeds the noise floor3dBAnd above, ieSNR≥3dB;

2, the total correlation of the waveform ≥70%.

The above shows the passage (PASS), otherwise it failed (REFER）.

04

Clinical application:

Newborn hearing screening: Otoacoustic emission is simple, rapid, non-invasive, easy to operate, sensitive, etc. Therefore, the otoacoustic emission test is used clinically as a hearing screening test program for newborns;

Localization diagnosis of cochlear lesions: If there is no lesion in front of the cochlea, it can lead to otoacoustic emission, which proves that the cochlea is normal; if there is no lesion in front of the cochlea, it can not lead to otoacoustic emission, which proves that the cochlea may have lesions, because some normal people can not lead ;

Diagnosis of post-cochlear lesions: If the patient is a sensorineural hearing loss, the otoacoustic emission can be induced to prove the lesion after the cochlear; if the patient is a sensorineural hearing loss, the otoacoustic emission cannot be induced, which proves that the cochlea may have lesions but cannot exclude the snail After the lesion;

Diagnosis of central lesions: Otoacoustic emissions have a masking characteristic. If both sides can induce otoacoustic emissions, the otoacoustic emission threshold will be attenuated after the opposite side is given an acoustic stimulus. If there is no attenuation, the central nervous system may have lesions.