Behavioral Testing

As I've already mentioned, we went in for James's behavioral hearing test today. They do the test in a sound booth, a small soundproof room (pictured here).

The first thing they did was a quick test that puffed some air into his ears to test his eardrum responsiveness. The results showed a bit less than normal flexibility, which could mean that he has a little fluid behind his ears, or it could just be an individual difference. Either way, they didn't seem particularly concerned about it.

Then, they had Mike sit with James on his lap. The assistant (a graduate student) was in the room with us, and the audiologist was in the control room. (In the photo, the control room is behind the slightly shaded glass behind the table.)

The idea behind the test is to get the baby to turn and look at some boxes with dancing puppets when they hear a noise, and so you can use the response or lack of response to indicate what they're hearing. The boxes are the black things at the edge of the photo. They're dark glass, but when the baby turns to a noise, they light up and a stuffed animal inside moves around -- they have a lion who roars and shakes his head, an elephant that raises his trunk, and so on. The first part of the test is training to get the baby to realize that when they hear a sound and turn that direction, they'll be rewarded by dancing puppets. The assistant's job at first is to direct the baby's attention to the boxes, and then for the rest of the test, her job was to be "interesting but not too interesting" -- that is, keep James's attention focused elsewhere so that they could make the sounds when he wasn't already looking at the boxes.

The training part went very quickly for James; he got the idea in just a couple of tries. And he loved the puppets! Every time they appeared he would get a big smile and talk to them. It was so cute!

The assistant had a whole range of toys, from a ball with glitter water inside to trucks and small animals. (Her task was more difficult because we all had to remain silent, so she couldn't distract him with talking!) Every time James started to lose interest in one toy she'd pull out the next one. The sounds came from speakers that are in the corner behind where I'm standing in the picture. They ranged from static-like noises to Star Trek/space age type noises. When he heard them he would perk up and turn to the boxes. The tricky part was that he sometimes turned around to check out the boxes just to see if anything was happening there, so occasionally it was hard to determine if he actually heard a particular sound -- when that happened, they just tried it again later.

After the first round of testing, they put James in a high chair for the second round, and I got to go into the control booth and see it from the other side. For the second round the audiologist started at 10 decibels lower than where he'd responded the previous time at each pitch, to see if he could hear quieter sounds. It seemed like he was fairly consistent, though, which was nice because it gave us reasonable confidence in the results. For part of the session, they also put a device that looked like a headband on his head to do a bone conduction test, which sends sounds directly to the inner ear.

James really did a wonderful job; he was so happy and attentive. Sometimes they have to try multiple sessions to get a good test, so it was great that he managed it the first time around. In fact, the testers complimented him on his cuteness and his developmental skills. :)

The results indicated that he had reasonably good (although not completely normal) hearing at lower pitches, and it got progressively worse as they moved toward the higher pitches (so, it took a sound of about 70 decibels for him to react at the highest pitch). They chart the results on a grid called an audiogram with decibel level (loudness) on one axis and pitch on the other, and so his line looked like a diagonal. Apparently this is a fairly typical pattern for kids with sensorineural hearing loss.

They told us that the loss was in the mild to moderate range, which actually seemed pretty encouraging to us. And this is a range that is generally very correctable with hearing aids. And because James did so well with the testing, they felt comfortable recommending that we go ahead and start the process of getting his hearing aids. (Their perspective is that the sooner kids get the amplification they need, the better -- which makes sense because once they can hear at normal levels, they'll pick up a lot more language.) They'll do a couple more tests to get a more fine-tuned measure of his hearing (for example, testing each ear separately), but they were confident enough in the information that they had from today's test that they should be able to get the settings fairly close to what he needs. (If he does have some fluid in his ears, that might affect the results a tiny bit, but probably not much.) The audiologist also said that if she had a six year-old, for example, with the same pattern of hearing loss, she'd be able to carry on a conversation with him even if he didn't have his hearing aids, but she might have to raise her voice a little and wouldn't lower her voice. So that's also kind of nice that he wouldn't completely miss out on things if for some reason he didn't have his hearing aids in.

The first step (besides knowing the hearing levels) to get hearing aids is to make an ear mold, so they did that today as well. They put a little cotton with a string on it in the ear first, and then they squeeze this pink stuff that looks like Silly Putty into the outside of the ear. It dries in a few minutes, and they use the string to pull it out, so they have a model of the ear shape. The hearing aids for babies have one part that goes inside their ear, and then another part that fits around the back of the ear. They have a bunch of different colors and a few patterns you can choose from, and apparently older kids enjoy picking out fun patterns.

The next step is an appointment to do the fitting, and they're going to try to do that before his surgery; we'll see if the scheduling works out.

Apparently the big challenge at his age is that the kids grab them and take them out of the ears and try to put them in their mouth. :) (Surprise!) They have little hats they can wear for a while until they get used to having the aids on or until they grow out of that particular phase.