Nolan's "third site" hearing test is scheduled at Buffalo Children's (WCHOB) on Wednesday. People often ask why Nolan is underamplified, and there are a few reasons for his amplification difficulties. One reason is that his hearing levels fluctuate- his high frequencies have been anywhere from mild to moderately severe (currently at moderately severe). When his hearing dips, the amplification is insufficient to get him above the speech banana in the high frequency ranges. This is the reason that he has completely lost his high frequency sounds, and can only hear them with an FM system (his aided thresholds are in the moderate range in the high frequencies).
The other reason is that part of his hearing loss may be an idiopathic conductive hearing loss. Conductive hearing losses often take more power than a sensorineural hearing loss, and the DSL programs for programming hearing aids are based on sensorineural hearing loss parameters. In other words, Nolan's hearing aids aren't programmed appropriately due to the recently discovered nature of his loss. Without aided audiograms (our current audiology clinic refuses to do them), we are not able to get his low frequencies set to the right levels.
As a recap, we have had several different results for Nolan's hearing levels. We obtained Nolan's first bone conduction scores back in May of this year (this should have been performed with his newborn ABR testing). At the age of two-and-a-half, this is what his audiogram looked like:
His air conduction scores were in the moderately-severe rising to mild category. His left ear was the better ear. His bone conduction score was a rising configuration, indicating that his cochlear (or sensorineural) loss was consistant with his newborn ABR testing.
Then we went to John Tracy, and the testing there resulted in this audiogram:
The testing obtained at John Tracy indicated a conductive loss for all frequencies below 2000Hz, and a sensorineural loss 2000Hz-4000Hz. In other words, his cochlear hearing loss is in a traditional sloping pattern. The conductive hearing loss in the low frequencies will require more power to obtain access to the speech banana. It is interesting to note that the left ear (which was mild in May) shows a moderately severe air conduction threshold, with no appreciable air-bone gap. In other words- his high frequencies have a fluctuating sensorineural hearing loss. We have seen his hearing levels go up and down in this frequency range over the past two years. His low frequencies are conductive, but relatively stable.
With such different test results, we returned to our current audiologist in Buffalo to repeat the bone conduction testing. We achieved these results:
I used the air conduction thresholds obtained in May, since we didn't get any air conduction testing run. The bone conduction testing in August demonstrated a conductive loss at 500Hz (consistent with John Tracy), and a mixed loss at the other frequencies.
With three different bone conduction results, we need to get a "referee" test to determine which is the most accurate. The audiology department at WCHOB will be running bone conduction, air conduction, and hopefully aided testing.
Hopefully, with a proper hearing loss diagnosis, we will be able to manage his amplification better and will have a clearer picture of how his hearing loss fits in with his other medical issues. Unless, of course, we get yet another "different" hearing loss picture- hopefully the WCHOB results will match the John Tracy results or the original Buffalo results. Then we can find someone to take Nolan's declining articulation scores seriously and get his amplification set to appropriate levels.
We really want to get his plurals back!