My daughter received a standard newborn hearing screening during our stay in the hospital following her birth. The man who performed the screening had to come to our room three times to find time when we weren’t otherwise occupied by doctors or nurses.
Since my daughter Arya had a difficult delivery, our hospital room was frequently occupied by medical staff during the two days of postpartum stay. I’m not sure why the hospital doesn’t have a master schedule for each patient rather than relying on random luck.
The man who performed the screening was polite when he finally found our room free of other hospital staff. It took a few minutes for him to setup his equipment near my wife’s bed. The hearing screening equipment looked like a big, ugly, rectangular, white box on wheels with wires sticking out from weird holes.
My daughter slept through the hearing screening. She was comfortably swaddled in a blanket and snuggled next to my wife in the hospital bed the entire time. The screener first tried a method called Otoacoustic Emissions (OAE) which involved placing little probes into my baby’s ears.
The probes, which looked like tiny earbuds, kept falling out since they did not fit properly. He tried two different size probes looking for the one that fit into my daughter’s ears. He also had my wife try to hold the probes in, but he gave up that method of using the probes after a half dozen attempts.
I discovered later that the OAE method is supposed to measure the sound waves produced in the baby’s inner ear by evaluating the echo from tiny clicks played through the probes. Obviously the method doesn’t work if the probes won’t stay in the baby’s ears.
I found it ridiculous that the hospital has a full-time hearing screener with a fancy machine, but only has two probe sizes. The cost of buying a probe must be a fraction of the cost of the screener’s weekly salary.
After giving up on the failed method the screener moved to a different technique. The second method, called Automated Auditory Brainstem Response (AABR) required putting cute little earphones over my daughter’s ears and having my wife hold two white pads on Arya’s head.
He seemed happier with the AABR technique despite the fact that the white pads kept slipping around Arya’s head. The pads weren’t held on by any sticky substance and my wife didn’t want to push hard enough to keep them in place. So whenever Arya moved her head (multiple times a minute) the pads would slip a little from their initial position.
The AABR method is supposed to measure how the hearing nerve in the baby’s brain responds to sound. Our screening used what looked like baby-sized earphones to generate sound. The earphones stayed on Arya’s head the whole time so I assume the sounds were generated properly.
The white pads on her head were there to measure Arya’s hearing nerve responses to those sounds. The screener repeated the AABR multiple times — I assumed to try to compensate for the pads moving — until finally reaching his conclusion.
He told us our baby flunked her newborn hearing screening.
Following my barrage of follow-up questions, I learned some information from him:
- 95% of newborns pass the hearing screening
- Of the 5% that fail, a large minority have no actual hearing loss
- Failing the test could be due to fluid or wax (called vermix) blockage, movement, or hearing loss
We also received an appointment 6 weeks later for a more comprehensive hearing test at a specialized diagnostic center with a trained audiologist specializing in hearing loss in newborns. We won’t know anything more about Arya’s hearing for at least 6 weeks.
I found more general information about the process of newborn hearing screening from the American Academy of Pediatrics, two different WebMD properties, and a site run by the BoysTown National Research Hospital in Nebraska. I also read a highly relevant study listed in the PubMed database run by the National Institutes of Health.
The study (Korres et al, 2008) screened 76,560 newborns in the hospital following birth and 1564 (2%) failed the initial hearing screening. 541 newborns were tested again one month later with 1023 dropping out and failing to get tested. Of the 541 who actually showed up for the second test, 303 (56%) were normal.
Having read the study and several other confirming articles, there is a reasonable chance that Arya’s hearing is fine. Unfortunately, we have no way to tell under 6 weeks from now when we go back for the full baby hearing diagnostic test.
I hate the long delay between flunking the newborn hearing screening and confirmation of the results with the longer hearing diagnostic test. I understand the main reason for the lag is to ensure that the temporary issues such as blockage will clear up prior to the full diagnostic. However, it is unpleasant to not know for more than a month whether our baby is deaf.
For now we’ve read all the information available from the Centers For Disease Control and Prevention about newborn hearing loss and we are prepared for the worst even while we hope for the best.