Children with hearing loss should receive audiological evaluations on a regular basis. But what happens with the test results? Audiologic evaluations are not just an exercise – they are a critical part of planning management. In order to use the information well, it is important to be able to carefully review the audiologic evaluation and interpret the test results.
Degree of hearing loss
Degree of hearing loss tells us something but not everything we need to know. Degree of hearing loss gives some information about what to expect but we should not assume that degree of hearing loss determines what a child is capable of. The important information we need to learn from degree of hearing loss is that it helps us select technology. It is important to remember that ANY degree of hearing loss will effect language and literacy. Mild hearing loss is not a mild.
Determining what is needed – unaided testing
After determining degree of hearing loss it is important to determine something about function. For infants, we can systematically assess their ability to respond to Ling sounds. If a child is old enough to understand speech then critical information will be obtained by evaluating unaided speech perception. What does the child hear and understand at a normal and soft conversational level without technology. This critical information helps everyone understand what a child is hearing, and more importantly, what a child is missing. If a child demonstrates anything less then excellent speech perception skills (90-100%) in any of the test conditions, the child will likely benefit from some form of technology.
Interpreting aided test results
The one and only goal of technology is to provide sufficient auditory access for language, literacy, academic learning and social skills. It is ABSOLUTELY ESSENTIAL that we measure how the child is hearing with technology. If a child does not have sufficient auditory access we can’t expect them to learn. So what do we have to look for?
Real Ear Assessment provides important information but it is an estimate and only an estimate. Real Ear testing is NOT measuring hearing. It is a measure of sound reaching the tympanic membrane. If we want to know how a child is hearing we have to test the child.
Aided thresholds – The same methods that are used to test hearing can be successfully used to obtain thresholds with hearing aids or cochlear implants. Aided testing lets us know if a child is hearing at sufficiently soft levels. Our goal is to have a child ear at sufficient soft levels to hear speech in most situations – at the top of the speech banana. If a child hears well for low and mid frequencies but does not hear high frequencies, he will be missing sibilants, fricatives etc. which will significantly impact language.
Hearing at normal conversational levels – First, we need to know what a child is hearing in each ear separately and with both ears together. Ideally, we want to see that a child has excellent speech perception scores in each ear separately at normal conversational levels in each ear and binaurally. If a child hears well at normal conversational levels she will be able to understand people talking who are within a few feet when there is little or no competing noise. If a child does not hear well at normal conversational levels, it means that we can expect the child to have difficultly hearing if the talker is more then a few feet away. Let’s think about what this means for a child in the classroom? If a child does not understand speech clearly at normal conversational levels, it will be necessary to find alternative ways for the child to receive classroom information. Considerations might include, but not limited to, an FM system.
Hearing at a soft conversational level – While hearing at a normal conversational level is important it is also important for a child to hear and understand speech at soft levels. Hearing at soft levels allows a child to overhear conversation and to hear comments from other students at a distance. If a child cannot hear speech at soft levels, he will have difficulty following classroom discussion. If we do not have information about how a child hears soft speech we will not be able to determine whether assistance is needed to hear in the classroom. If a child has anything less then excellent hearing for soft speech, we know assistance will be needed and an FM system with a pass around microphone is the first thing we should consider.
Speech in competing noise – While it would be nice it the world was quiet, it isn’t, so it is essential to measure how a child hears when there is background noise. If a child hears well with competing noise there is a good chance that the child will do well in most situations. However, if a child has difficulty hearing in competing noise it means that we need to find other ways to provide access to critical language and other learning information.
A note about speech perception testing
In addition to being sure that we are testing in all the necessary test conditions, it is also critical that we select the appropriate speech perception tests. If a child is in 3rd grade, we need to test the child using a speech perception test that uses vocabulary she will be exposed to in 3rd grade. While a child may do very well using a test which uses kindergarten words, that test will not help us to understand how the child is hearing in the classroom in which he is being educated. Tests must be at the appropriate level of difficult to be useful.
Using test information
By reviewing the test information we can get a good understanding about how a child is hearing and what to expect at home, in the classroom and on the playground. If the information is not clear, parents, teachers, speech-language pathologists and auditory-verbal practitioners should feel free to go back to the audiologist and ask for clarity. If all tests have not been completed, ask why? If we find that a child we are working with is not hearing high frequency sounds, or is not hearing at a distance, we need to go back to the audiologist and express our concerns. The audiologist should be listening and should do all he can to improve the technology settings to solve the problems the child is having with auditory access. If hearing aid settings cannot be improved, is it time for new hearing aids? Is it time to consider a cochlear implant? As long as the team is communicating, listening to each others concerns, and working together, kids we be the best they can be.