- In this video,
I'm explaining one of the most important
digital hearing aid features, compression, coming up.
(rich, hip instrumentals)
Hi guys, Cliff Olson,
Doctor of Audiology and founder of Applied Hearing Solutions
in Anthem, Arizona, and on this channel,
I cover a bunch of hearing-related information
to help make you a better-informed consumer.
If you're into that,
make sure you hit that subscribe button.
And don't forget to click the bell
to receive a notification every time I post a new video.
One of the more difficult hearing aid concepts
for me to grasp when I was an audiology student
at the University of Illinois
was this concept of compression,
but with enough persistence from my instructor,
Dr. Mike Brown,
he eventually helped me understand what compression is
and what it does, so Mike, if you're watching this video,
hopefully I make you proud
with my explanation of compression.
The development of digital hearing aid technology
in the mid-1990s
gave birth to some pretty amazing digital features
inside of today's modern hearing aids.
But perhaps one of the most important features
that this gave birth to was compression.
Compression is used to make a broader range of sounds
audible to a hearing aid user.
Think of it like this.
If you have an individual who's speaking softly to you
and an individual who's yelling at you,
you need to provide a different level of amplification
to each one of those individuals.
For the soft-spoken individual,
you need to apply more amplification to their voice
so you can audibly hear them.
For the individual who's yelling at you,
you need to provide significantly less
amount of amplification to them.
Otherwise, they're gonna be way too loud for you.
Before compression,
you could only apply the same amount of amplification
for each one of those individuals,
making the soft-spoken person potentially too soft for you,
and making the loud individual way too loud for you.
Individuals with normal hearing have a large range of sounds
that they can hear.
We call this the dynamic range.
They can hear very soft sounds
and they can tolerate louder sounds at the same time,
giving them a wide range of sounds that they can hear
and hear comfortably.
However, individuals with a hearing loss
have a smaller dynamic range
because their hearing loss
requires that sounds need to be louder
before they can barely hear them, and oftentimes,
louder sounds become uncomfortable at a lower level.
This creates a very narrow range
that all sounds must be compressed into
if they want soft sounds to be audible
and loud sounds to still be comfortable.
When a hearing care provider
is programming a set of hearing aids for you,
they need to ensure that they're programming in
the correct amount of amplification for loud-level sounds,
average-level sounds,
and soft-level sounds all at the same time.
This is completely different than just adjusting
the overall amplification at different frequency bands.
In my opinion,
the best way to ensure that this happens correctly
and that you get the right amount of compression
is by using real ear measurement.
Now, if you don't know what real ear measurement is,
I highly recommend that you watch my video
that I will link in the description.
Now, bare with me for this next part
where I explain compression.
I promise it will be worth it.
This is how it works.
When programming a set of hearing aids,
a hearing care provider can adjust the amount
of amplification you receive from a loud-level sound,
which we would consider an 80 decibel input,
an average-level sound at 65 decibels,
and a soft-level sound at 50 decibels.
The higher the numbers are in these boxes,
the more amplification is given to that loud, average,
or soft-level sound input at each frequency.
The amount of compression is also usually illustrated
in the software.
In this case,
the Phonak Target hearing aid software
has the compression ratio
right below the amplification numbers.
The higher these numbers,
the more compression we are applying to these sounds.
When using real ear measurement
to verify the correct amount of amplification
and compression for your hearing aids,
loud, average, and soft-level speech sounds
are presented from a loud speaker in front of you.
The amplification levels of your hearing aids
are then measured inside of your ear canals
with a probe microphone
to determine if the correct amount of amplification
is being given for each of these sounds.
Your hearing care provider will make adjustments
in the hearing aid programming software
until they match the amplification
of your prescriptive targets.
What you're looking at here is amplification measurements
taken inside of a patient's ear canal.
The goal is to match the solid lines,
which is the hearing aid amplification,
with the hash mark lines,
which is the prescription for each of these sound inputs.
The measurements for average speech sounds are in purple,
loud speech sounds are in red,
and soft speech sounds are in turquoise.
If your hearing care professional
matches these targets accurately,
it will ensure that loud, average, and soft sounds
are correctly amplified
with the right amount of compression.
When we are done making adjustments,
we can clearly see that we are giving
a different amount of amplification to each input level.
The smaller the numbers,
the less amplification we are giving to those sounds.
And the larger the numbers,
the more amplification we're giving to those sounds.
In this case,
loud-level sounds receive the least amount of amplification,
and soft-level sounds receive the most.
Essentially, we're giving more amplification
to that person who's speaking softly to you,
and less amplification to that person who's yelling at you.
That is compression in a nutshell.
All right guys, that should give you a very
basic level understanding of what compression is.
Now, there are a ton of other things that I could talk about
with compression, but this video would be over an hour long.
That being said,
hopefully this gives you a better understanding
of what your hearing care professional's
actually trying to accomplish
when programming your hearing aids,
and it is a lot more complex
than just increasing or decreasing the overall volume.
While compression is not as exciting as other
hearing aid features like Bluetooth
or automatically-adjusting program settings,
it could quite possibly be
one of the most important features
inside of your hearing aids.
That's it for this video.
If you have any questions,
leave them in the comments section below.
If you like the video, please share it.
If you wanna see other videos just like this one,
go ahead and hit that subscribe button.
I'll see ya next time.
(upbeat, pop music)