Unfortunately, the world is a noisy place. That’s bad enough for a child with normal hearing, but it is absolutely dreadful for a child with a hearing loss. Why? Well, children learn more than 80% of what they know through incidental learning. That means they learn by overhearing things around them. We all have had experiences when we said something to one person and the child (who was not part of the conversation) pops up and says “Why did you say…”? At that moment, it is quite annoying to have the child “listening in” to a conversation that is not directed at him. But think about what an enormous learning experience it is for a child to be exposed to all that language! If a child has to rely on direct teaching for what they know, their language will be significantly limited.
Do Children With Hearing Loss Have Problems With Incidental Learning?
In order to make use of incidental learning, children need to hear speech from a distance. They need to be able to hear soft speech, and to hear it clearly. How do we know if a child can hear well enough to overhear? And, if they can hear the speech of someone standing 10 feet away, is it clear? We only know the answer to these questions by testing the child in difficult listening conditions.
What do we want to know?
Can the child hear soft speech? We need to know this because incidental learning means overhearing things that are not directed to you but are, usually, at a distance. So, almost by definition, it will be softer than speech that is directed to you. We also need to know how a child hears speech when there is noise – since there is almost always noise. When I test children, I test their ability to hear normal conversation, soft conversation, and speech in noise. Normal conversation is at 50 dBHL, soft conversation is at 35 dBHL, and when I test in noise, I test at normal conversation with noise slightly softer than the speech (50 dBHL+5 SNR). I choose these levels because I believe that they are typical listening situations.
One case example
Here is Molly who has a moderately-severe hearing loss. She wears two hearing aids and is in third grade at her local school. She is doing well but seems to learn better when she gets information from something she is reading rather than from listening in the classroom. We need to test her to see how well she is hearing in the classroom.
We tested her with each hearing aid alone and with both together.
|Right HA||Left HA||Binaural HA’s|
|50 dBHL +5 SNR||64%|
Looking only at the normal conversational test results it appears that Molly is hearing fairly well. She is missing some information but hearing a lot. But when we look at her ability to hear soft speech and speech in noise she is clearly struggling.
What do these test results mean in real life?
These results explain why Molly is relying on written material to learn. She cannot hear most of what is said around her. We need to see if there is anything we can do to her hearing aids to help her hear better. If we cannot, we need to consider changing hearing aids until we find hearing aids that meet her needs.
Would an FM help?
Absolutely, but it will only help in school if the teacher uses it all day and if she repeats every comment made by every student in the room – whether or not it seems relevant to the classroom discussion. The FM will not help in the noisy hallways, in the lunchroom or during recess because it is not used there. It will not help at home, at ballet class, at religious instruction, etc., again, because it is not used there.
What do we need to do?
Never assume. Every child (and actually every adult) with a hearing loss needs to be tested at normal and soft conversation in quiet and in noise. If we do not test, we do not know what the child can and cannot hear. Just do it!!