Monday, December 16, 2013

Post-NICU Hearing Test

Hearing loss can occur at anytime. According to the U.S. Centers for Disease Control and Prevention (CDC), there is an increased chance that a child will have hearing loss if he or she spent five days or more in a hospital Neonatal Intensive Care Unit (NICU) or had complications while in the NICU, among many other things.

Hearing screenings are vital for newborns and can detect conditions that, if left untreated, can cause disabilities, developmental delays, illnesses, or even death. If diagnosed early, many of these disorders can be successfully managed.

I've been a little concerned about Emily's hearing. She hasn't been responding to her name when I call her. And, she doesn't always look at toys when I bang them together behind her head. That being said, Emily does get startled by strange noises, such as a cough or a sneeze.

Emily failed her first hearing test in the Neonatal Intensive Care Unit (NICU). But, she passed her second hearing test on the day she was discharged.

Although Emily passed her  hospital hearing exams, I've been concerned about her hearing for quite some time. So, I took her for a post-NICU hearing test. The test was conducted by an audiologist.

NICU Hearing Test

There are many different types of tests that can be carried out to determine hearing ability, based on the age of the person involved.

In the NICU, Emily received an auditory brainstem response (AABR) test while she was sleeping. Headphones were placed on her ears and probes were put on her forehead to measure her hearing ability. The headphones emitted clicking sounds in the ear. If she could hear the click, then brain wave activity in response to the sound was recorded.was measured from the probes on her forehead.

Post-NICU Hearing Test

Emily's post-NICU hearing test consisted of two different techniques.  The first hearing test examined behavioral reactions, while the second measured cochlea responses.

Behavioral Test

The first part of Emily's post-NICU hearing exam used a technique called visual reinforcement audiometry. The test was conducted in sound room with four speakers. I held Emily in my lap facing a window. The audiologist sat on the other side of the window and projected different types of sounds through the speakers. When Emily heard a sound and turned her head toward it, she received a reward -- the appearance of Mickey Mouse or Goofy -- complete with flashing lights and clanging noises. The audiologist encouraged this type of behavioral response by providing this type of reward each time Emily turned towards the projected sound. The audiologist also recorded Emily's behavioral responses (i.e., head turns, vocalization, and arm and eye movements) to assess her hearing ability.

Although Emily was very quiet and reserved when she heard the soft sounds of ocean waves, she was very responsive to louder noises. The audiologist indicated that this was typical for a baby of Emily's age (11 months, 8 months adjusted).  Accordingly, Emily passed the behavioral test with flying colors.

Cochlea Test

The second hearing exam Emily participated in was an otoacoustic emissions (OAE) test. A small earpiece containing a microphone and mini-loudspeaker was placed in the ear. The loudspeaker made clicking noises in the ear, which were then passed to the cochlea.

Thousands of nerve cells, called hair cells, are inside of the cochlea.  Each hair cell picks up a different sound.  The cells work together to send the sound to the brain where the sound is heard and understand.

During Emily's test, her cochlea responded to sounds by sending a sound back to the ear canal which was detected by the microphone.

The cochlea test was performed on one ear at a time. Emily was very interested in the earpieces -- and kept pulling them out, so this simple and painless test took quite some time.

Test Results
Emily passed her post-NICU hearing exam. We will schedule a follow-up exam in six months -- just to be sure that there are no changes.

Although, I am pleased that Emily passed her test, I am still concerned about her lack of responsiveness. Perhaps Emily just selectively listens?  Or perhaps she tunes out certain noises (which could be a skill that she learned in the NICU)?  Or, maybe Mommy and Daddy are simply too boring to listen and respond to (kind of like the adults in the Peanuts cartoons)?  Who knows!

Your Experience

Did your baby have a post-NICU hearing exam?  What was your experience?

1 comment:

  1. Happy to know that these tests are available and that Emily did so well!