Harvey Dillon has just published the second edition of Hearing Aids (Thieme, 2012). Harvey is very well known and writes and speaks frequently on this topic. He is a very thorough researcher who has set a very high standard for clinicians. Harvey has written a lot about pediatric hearing aid fitting. In my text book (Madell and Flexer, Pediatric Audiology: Diagnosis, Technology and Management, Thieme 2008) Harvey wrote the hearing aid chapter with Theresa Ching and Maryanne Goldberg. He made some pretty startling statements in that chapter that significantly changed the way technology was fit on children.
Which things changed?
In general, people are fairly conservative about fitting hearing aids on children. Because children cannot tell us what they hear, and because many audiologists do not test children (or adults) with technology to see if it is working well, audiologists have been reluctant to use some of the new strategies. Dillon and colleagues suggested that the new technology is so good that we should be using noise reduction and directional microphones on everyone – kids and adults. That was a very dramatic concept and significantly changed the way manufactures suggested hearing aids should be set for kids. Dillon points out that many pediatric audiologist do not want to try new strategies on children until they are proven. How will they become proven if we do not try them?
Are all strategies the same?
Why are people cautious about trying the new strategies on kids? I can understand some of the concern about directional mics on very little kids. A direction mic works best if the person using it can direct the microphone towards the person speaking – in other words, turn his head to face the talker. Little children may not be able to do that. So maybe it is a good idea to wait a little while until the child is starting to understand language so he will start to turn towards the speaker. Noise reduction is different. The world is noise and we know that noise interferes with what kids can learn so getting rid of noise is definitely a good idea. Some audiologists are concerned that the noise circuit turning on and off will be distracting to children. But listening in noise is also distracting.
Dillon also discusses frequency lowering technology and points out that the research is really not clear and that we do not know for who it will and will not work. Try it and test it before you recommend it for a particular patient. He also discusses how important a close microphone (FM) is for improving hearing and reports that with a close microphone people with hearing loss may hear better than their normal nearing counterparts.