Auditory Processing – Hearing Acuity – Ear Structure


>>So, Devon, auditory processing and hearing
acuity, they sound like big words, what’s the mystery?>>Hearing acuity refers to the very softest
sound we can hear across a range of frequencies. The human ear can hear up to about 8,000 hertz
which is how we measure frequency or cycles per second in the old language. So when we
have our hearing tested we’re looking at that range of sounds – the very softest
sound we can hear across those range of frequencies. So we look at loudness versus softness and
low versus high frequency, and hearing acuity happens just within the ear, particularly
in the cochlear.>>So, when we think about dogs being able
to hear very high sounds they can hear much higher than 8,000 hertz?>>They can I believe.>>Right, so that’s why when we listen to
their whistles we can’t hear anything?>>That’s right.>>Right, okay, so, how does hearing acuity
then link in with auditory processing and our ability to learn?>>Well, to start off with, we will not learn
language if we can’t hear. Hearing is fundamental to learning language and many things can impact
on a child’s development of their auditory processing if their hearing is interrupted
in those early years.>>Right, okay. So, if there’s a gap in
the hearing or if a hearing problem isn’t diagnosed early then the problem is compounded?>>Exactly. We know in children their ear
structures are very small so they’re very prone to ear infection or glue ear which is
an accumulation of fluid in the middle ear which prevents the sound signal getting through
to the inner ear.>>Okay, so in a classroom situation, getting
back to what we said before, if you’ve got a really noisy classroom someone who’s got
a hearing acuity problem is going to be struggling big time, right?>>Absolutely, yes, and we need to distinguish
between hearing acuity and auditory processing, but hearing acuity is the very first thing
we need to look at because we need to know how well the child hears before we can assess
how they process what they’re hearing, and obviously if you have a hearing loss that
will affect your processing.>>Yeah, so if you’ve got a student who
is looking like they are perhaps not getting the message or something like that, is it
worthwhile perhaps having a chat to someone saying, ‘Look, maybe this person just needs
to have their hearing tested’?>>The very first thing you would do would
be to make sure they have a hearing test and check out that there’s no structural issue
with their hearing acuity.>>Right, because there is a direct link between
hearing acuity and the ability to learn?>>Absolutely. In a classroom, you know, if
you’re not hearing properly you won’t learn, but also there are that whole group
of children that we’re talking about who have fine hearing acuity but don’t process
effectively.>>Yeah, I was going to ask you about that,
so if one of the two isn’t working that’s enough to cause a problem?>>Yes.>>Right, okay, it sounds pretty obvious I
guess, so let’s take it to the next level then, what if someone actually has both of
those problems, is this a disaster or can we treat it?>>Oh it’s all very treatable. If there
is a hearing loss first of all we’d want to know what’s causing that. We have two
kinds of hearing loss, one we call a Conductive Loss where there’s a blockage with the sound
going through at the level of either the ear canal or the middle ear.>>Right, okay.>>The ear basically has three parts: the
ear canal is the thing that you shouldn’t stick anything sharper in than your elbow.>>That’s the bit on the outside right?>>That’s it, the canal where the sound
goes. Then we come to the eardrum and then beyond the eardrum is what we call the middle
ear which is basically an air-filled cavity which has a connection through the back of
the throat called the eustachian tube and the job of the eustachian tube is to keep
the air pressure equal on the eardrum. Now, in many children, particularly small children,
it’s the middle ear that can fill up with fluid or when they develop an ear infection
the middle ear becomes full of junk you could say, or muck. So what happens is, sound travels
through the air – sound is just vibration – so the job of the eardrum and the little
bones in the middle ear, the osicles, they vibrate and they transfer that vibration to
the inner ear. The inner ear is where we have the organ of hearing, the cochlear. So, if
there’s any disruption to either the ear canal – and that can be just a build up
of wax in the ear canal which can cause hearing loss – or something going wrong in the middle
ear with a build-up of fluid or an ear infection, that sound vibration can’t effectively be
delivered to the inner ear where we actually hear. So, a Conductive Hearing Loss refers
to something going wrong in either the ear canal or the middle ear.>>Okay.>>Some children then can have a problem with
the actual organ of hearing itself, the cochlear.>>Yes.>>We refer to that as a Sensory Neural Loss.>>Okay.>>They can’t be treated.>>Right?>>Well, unless today if it’s a profound
loss they might get a cochlear implant, so that’s the wonderful thing today with technology.
Conductive Hearing Problems are very easily treated. So if it’s a chronic middle ear
problem with fluid build-up you might have heard of grommets…>>Mm, yes.>>so they insert a little tube a bit like
a mini cotton reel…>>Or they cut a hole in the drum so to speak.>>That’s right, they make a little hole
in the drum, put a little drainage tube in and that drains the fluid from the middle
ear. That’s very easily treated/>>So it sounds to me like there’s a bit
of a, if you like putting it into computer terms, there’s a hardware and software issue
here. So, you can have a hardware problem and a software problem, so there can be as
you said, a neural issue happening, and that’s the processing part and then there’s the
physical bit which is the acuity part?>>Well even the neural bit really can, even
before we get to do that processing, if there’s a problem in the cochlear that’s going to
affect your hearing acuity.>>Right, okay, well this sounds like it’s
getting even more complex, we’ll see what happens in further videos. Thanks Devon.

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