When we do a hearing assessment, there are
three parts to the ear: there’s the outer ear, the middle ear, and the inner ear. A
thorough hearing assessment includes an evaluation of each one of those parts. The first thing
that I’m going to do is what we refer to as otoscopy. And I’m going to look in the ear
with a light. And this is just a physical exam so that I can evaluate the condition
of the outer ear. Ok, so the next part of the assessment is to evaluate the hearing
sensitivity. So this stage involves listening to some sounds at different pitches. So if
you think of it like notes on the piano, the person receiving the test will hear a variety
of different notes. And what they are required to do is let me know what the softest sounds
are that they are able to hear. And the way this is done is–they can respond in a variety
of ways. Some people will ask you to raise your hand. In this case, we have a button
and the client can push the button each time they hear the sound. Just make sure these
are…Ok, so Brian I’m just going to put these earplugs in your ears, and I guess I’ll go
over and play some tones for you. Ok and there we go. I’m just going to play some tones in
your right ear first. Each time you hear one, just press the button, even if it’s very very
quiet. Ok so I’m starting at a level where I know he can hear, and then I go down in
steps of ten decibels each time. And each time he responds, I go down by ten decibels
again, until he doesn’t respond. When he doesn’t respond, you go up in steps of five. And what
this is called–it’s something we refer to as a bracketing technique. So we’re going–we’re
trying to determine the softest level that he can hear, at least two out of four times.
So the first frequency that we’ve evaluated is one thousand hertz, which is kind of in
the middle of what we’ve referred to as the speech frequencies. So next we’ll go up to
two thousand. Again, I’ll start at a level where I know he can hear, and then I’ll drop
down in steps of ten decibels each time he responds. And you try to change the delay
between the presentations of the tones so they don’t get locked into a pattern or into
a rhythm. Ok so he responded there, so we’ll drop it down by ten. He doesn’t respond. We’ll
go up in steps of five until he responds again. So then we go up to the next frequency. And
we do this for frequencies from 250 hertz up to 8,000. And as you can see, he’s got
excellent hearing. What we’re measuring is–we’re measuring the level of the frequency in a
unit that we refer to as decibels hearing level. And what that means–it’s referenced
to audiologically normal young adults. So zero dB HL, when we get down to zero here,
right there, that doesn’t mean that there’s no sound. That represents the average hearing
sensitivity of audiologically normal young adults that were sampled to generate this
measure. And for adults we say that a result that is 25 dB HL or better. So 25 dB HL or
less is what we refer to as the normal range of hearing for adults. And for children, the
reason we’re a little more stringent, is that they’re learning language. So a lot of those
very soft consonants and sounds that occur in speech, it’s really critical that they
hear those clearly in order to learn speech properly.