What are distortion product otoacoustic emissions (DPOAEs)?
Distortion Product Otoacoustic Emissions (DPOAEs) are acoustic signals that can be detected in the ear canal of a person with normal outer hair cell function, subsequent to stimulation of the auditory system with a pair of pure tones.
What are transient evoked otoacoustic emissions (TEOAEs)?
Transient Evoked Otoacoustic Emissions (TEOAEs) are acoustic signals that can be detected in the ear canal of a person with normal outer hair cell function, subsequent to stimulation of the auditory system with a series of wideband clicks.
Why measure otoacoustic emissions (OAEs)?
Available evidence suggests that otoacoustic emissions (OAEs) are generated by the cochlea’s outer hair cells, and that the presence of OAEs is an indication that the outer hair cells are normal. Although OAE test data provide no indication of inner hair cell function, or of hearing ability, current research indicates that the majority of hearing-impaired individuals will be identified by a simple OAE test. Patients who fail to generate OAEs should be rescreened and/or referred for additional audiological testing.
Patient preparation
Otoscopic examination of the patient’s ear canal should be performed prior to testing. Excessive cerumen or vernix in the ear canal may interfere with the test and give invalid or incomplete results. Patients with excessive cerumen, debris, or foreign bodies in the ear canal should be referred to an audiologist or physician for removal of the blockage prior to testing. Place the patient in a position that will allow the OtoRead™ to be held steady while testing is in progress. The patient should remain still and quiet while the test is performed.
How to perform OAE testing with OtoRead™
- Place an ear tip as far down as possible on the probe tip.
- Turn on the OtoRead™ by pressing the large DOWN arrow button.
- Select the test ear by pressing the LEFT or RIGHT arrow key.
- Insert the ear tip deeply into the patient’s ear canal to obtain a seal. The ear tip must seal the ear canal. The best test results are obtained when the eartip is inserted deeply into the ear canal instead of flush with the ear canal opening. Caution must be taken, however, to ensure that the eartip does not extend too deeply into the ear canal. When a seal is obtained, the OtoRead™ will automatically begin the test - first calibrating and then testing emissions. Once the testing is finished, the unit will display “PASS” or “REFER” on the LCD display
- When testing is completed on both ears, turn the printer on and place the hand-held unit in the cradle. The most recent test results for both ears will automatically print out.
Test techniques
When testing a newborn or infant with the OtoRead™ instrument, the following suggestions might be helpful:
- The newborn has to be relatively quiet and calm; it is usually preferred for the infant to be asleep.
- When testing a newborn, gently pull down and back on the pinna to straighten out the ear canal.
- The cone-shaped ear tips tend to insert deeper down into the ear canal than the mushroom-shaped eartips.
- Warming the ear tips prior to insertion also helps to keep the baby calm during testing.
