"Profound Hearing Loss"

I can't say we were really surprised since Max had already failed three preliminary hearing screens in the hospital, but it was a heavy dose of reality to get an official diagnosis from a Doctor of Audiology.

We took Max in Tuesday for a full hearing test. The screens in the hospital were simple pass/fail against some coarse threshold. This test was designed to reveal degrees of hearing loss broken down by frequency range.

The trips with Max out of the house are quite a production. If we're out during a meal time, we have the feed pump (for his NG-tube), insulated milk carrier, backup oxygen tank (for emergencies), diaper bag, and car seat carrier. At least we were able to get a temporary handicap parking tag so we don't have to schlep all this stuff as far.

The audiologist told us that Max should arrive as tired as possible since he would need to sleep through the test. We chose this audiologist because she was one of the few that administers hearing tests to infants without sedation. With Max' medical history, his neonatologist didn't feel comfortable with sedating him yet. Forgoing sedation takes much more patience since you have to calm down the baby enough to fall asleep immediately after the stimulation of a car ride, carrying through a medical complex, and being manipulated to have electrodes placed all over his head. It took a while (and I'll spare the details), but Max eventually fell asleep.

The test took over half an hour for each ear. Starting a low frequencies, a series of tone bursts is presented into the target ear with a sealed earphone. The tones occur in increasing volume while the audiologist monitors brain activity. In every frequency range for the left ear, the audiologist ended up going to the maximum volume capability of the machine, 122dB with no perception whatsoever. For reference, this is analogous to standing immediately in front of the house speakers at Ozzfest without realizing that a band is on stage. We noticed that he flinched a little whenever the 4kHz tone burst was at 122dB in his right ear.

The audiologist then attempted to test Max on another machine that was capable of producing test tones louder than 122dB. She wanted to accurately measure any residual hearing ability that may exist below the noise floor. This could tell us if the auditory nerve pathways are still intact. Unfortunately, Max woke up about this time and we had to abort any further testing on that day.

So our next step is to meet with an otolaryngologist to discuss getting fitted for special hearing aids. "Special" because there are only two companies that manufacture hearing aids that produce a volume loud enough for this particular therapy. They're informally called "boomer" hearing aids. They're not designed to allow Max to hear so much as provide stimulation to any potential residual hearing to prevent the auditory cortex from permanently atrophying through disuse until he is old enough for a potential cochlear implant.

As of 2002, the FDA now approves cochlear implants beginning at 12 months of age, although "off label" use is not uncommon as young as 6 months in the US (4 months in Europe). Another variable is that cochlear implants are historically mono, but binaural (stereo) implants are beginning to be more common. This post is getting long, and any potential cochlear implant surgery is months away, so I'll save those details for later.