Bone Conduction Hearing Test

Nolan, with balloon-cat hat and kitty face.

For a quick recap, we have a hearing test that shows a rising slope audiogram via bone conduction (January 2010 at Buffalo-BHSC) and a hearing test that shows a traditional slope via bone conduction (July 2010 at John Tracy).

Since these two test results are the exact opposite of each other, we wanted to get a third test to clear up whatever conductive component might exist to Nolan's loss. The test yesterday showed (wait for it)... a third configuration! BHSC managed to get bone conduction with masking, which means they managed to get the bone conduction scores in each ear, individually.

While I can't remember the exact numbers, he is showing something that looks like a shallow cookie-bite configuration in both ears. His bone conduction score was 25/30dBdB at 500Hz and dropped to 50dB at 1000Hz, then came back up to 40dB by 4000Hz. He was extremely reliable, so now the question arises: does he have fluctuating bone conduction levels in addition to fluctuating sensorineural levels?

Our test in January showed a conductive component, but only in the high frequencies. The test in July showed a large conductive component from 250Hz-1000Hz, with normal cochlear function in that range. The test yesterday showed a conductive/mixed component at 500Hz, but sensorineural across the rest of the testing range.

*Insert hysterical laughter*

The only thing we can be sure of is that his loss is fluctuating across all frequencies. Our audiologist is suspicious that something was missed on his CT scan- we need to take another look at his vestibular aqueducts. This is the only thing that causes an air-bone gap in the low frequencies with fluctuating hearing thresholds (the fluctuations occur when there is no fluid or infection present, so these changes in hearing level have nothing to do with his ear infections- we omitted those results). The next step is to see the ENT, to review the data and determine what to do next. This might include a FOURTH hearing test at an independent location, where we're likely to get a fourth result.

We did not do air conduction thresholds yesterday, except for a quick Speech Reception Threshold (SRT). His SRT is 55dB in one ear and 65dB in the other (my guess is that his infected ear is the one with the worse air conduction threshold).

Speaking of the infected ear, it looks pretty bad. I have to call the ENT this morning to beg and plead to get in. The amoxicillin did nothing for it, he's had it since the middle of July, and is now at risk for complications from a long term ear infection (namely, mastoiditis: something we'd really like to avoid).

Once we get the infection cleared up and talk to the ENT about Nolan's fluctuating hearing loss and random air-bone gaps that seem to shift frequencies, we'll go back to Buffalo for the air conduction scores (these are what he really hears and are in the moderately severe range).

It's really hard to set hearing aids for constantly shifting targets- our only solution may be more frequent audiological testing.