Newborn Hearing Screening

 

How is screening done?

Most screenings are done before the baby leaves hospital. For those babies who do not have screening completed by the time of discharge, the family will be offered a follow-up appointment usually at the local public health audiology clinic. Screening may be offered at other community sites in each health authority.

Screening is completed by BCEHP-trained personnel using standardized equipment and following provincial protocols. Two safe and effective screening methods are used:

Automated Otoacoustic Emissions (AOAE): A probe is placed in the infant’s ear that presents a soft clicking sound. Sound waves (emissions) generated by the outer hair cells of the cochlea in response to the stimulus are measured by the probe. Response detection is automated.

Automated Auditory Brainstem Response (AABR): Electrodes are placed on the forehead and nape of neck, and soft clicks are presented by earphones. The electrodes measure the neural responses to the clicks from the auditory nerve and brainstem. Response detection is automated.

Screening is a two-stage process:

• For those babies who have a clear response (pass) on the first screening test, no further screening is needed. A “pass” screening result means it is very unlikely that a baby has a hearing loss. The accuracy of hearing screening is estimated to be between 90% and 95%.
• About 25% of babies need to have a second screening test because the first screening did not show a clear response from one or both ears.

The risk for hearing loss increases ten fold for babies who do not pass the second stage screening. Babies who do not pass screening (in one or both ears) have a 1 in 10 to 1 in 20 chance of hearing loss. These babies are at a greatly increased risk of having hearing loss.

It is important that families understand the increased likelihood of hearing loss once a refer result has occurred on screening. When families are reassured that their baby’s hearing is likely fine, they may not follow-through on the diagnostic assessment process. This will delay the age of identification.

For babies who do not pass second stage screening:

If the second screening test does not show a clear response from both ears (a refer result), the family will be referred to the nearest public health audiology clinic that provides infant diagnostic Auditory Brainstem Response assessments.

The refer rate from screening is between two to three percent. Note that even if a baby had “refer” result in one ear only, it is important for the family to follow through with diagnostic testing. Babies with hearing loss in one ear are at risk for delays in learning, language and speech. There are also some indications that babies with hearing loss in one ear may develop a hearing loss in their other ear later on.