Anatomy of the Ear and Hearing Loss


Doctor: So we just finished with your hearing test,
and I’m just going to tell you the results really quick. So, looks like you have about a mild to moderate,
going down to about severe hearing loss, bilaterally. They’re pretty symmetrical. It’s sensorineural in nature. Also, we have frequencies here, if you kind
of see on this graph. The pitches, or frequencies go up to 8000 and
then you also have your really low frequencies here.. Narrator: Have you ever felt aggravated or confused
when your audiologist is explaining your hearing test and you don’t understand what’s going
on? Are you not the only one? To better understand hearing loss, let’s
talk about the basic anatomy of the ear and what could lead to the different types of hearing
loss. We have an outer ear, middle ear, and an inner
ear. The outer ear is what we can see on the exterior
and includes the ear canal, where earwax is produced. The outer ear helps to localize sounds and
funnels the sounds from the surrounding environment down our ear canal to our ear drum. From here, we enter the middle ear, which
is an air-filled space. The middle ear consists of very small ossicle
bones, known as the malleus, incus, and stapes. These three bones all work together to make sure
the sound energy reaches the oval window of the cochlea. If there is a problem in the outer ear and/or
in the middle ear, this is called a conductive hearing loss. For example, if your ear canal is full of
earwax and sound isn’t able to get through, or if there is a buildup of fluid in your
middle ear from a really bad cold, you won’t be able to hear well. Everything will sound soft to you and the
speaker will have to talk very loudly for you to hear. Imagine hearing like you just put earplugs
in both ears. Friend: Hey Tran. How’s it going? Tran! Hey Tran! How’s it going? Tran: Hi! I didn’t see you there! Friend: Didn’t see you either. Tran: So, how’s it going? Friend: Good, how are you? Tran: Good! Narrator: Now, let’s talk about the inner ear. This is where all sounds you’re hearing
in the environment are processed, down to the specific volume and pitch. The inner ear holds the organ of hearing called
the cochlea, which is filled with fluid. The cochlea houses hair cells that move in
specific areas and at different speeds, depending on what you’re hearing in the environment. When the stapes footplate pushes on the oval
window, cochlear fluid begins to move, and the hair cells move in response to the presence
of sound. The signals then travel to the auditory nerve,
leading up the brainstem and to the auditory cortex. If there’s a problem in the inner ear and
the auditory nerve, this is called a sensorineural hearing loss. When the hair cells in the cochlea move quickly
and frequently, the risk for damage increases and they will eventually break. Once they break, they don’t regenerate. The signals are unable to make it to your
auditory nerve, resulting in auditory deprivation and can lead to deficits in cognitive ability. So, imagine taking out your earplugs, and having
someone yell at you. Depending on the level of hearing loss, speaking
louder will not help with the clarity of speech. It’s helpful to ask the speaker to slow
down for better speech understanding. Friend two: Hey Tran, did you see the Bachelor last night? Tran: Hey, you don’t have to yell. I have a mild hearing loss. But no, no I didn’t. I just can’t really understand what you’re
saying, so can you just slow down your speech? Friend two: Okay. Narrator: If there is a problem with the sound traveling
through, and in the way it’s processed at the auditory nerve, this is called a mixed
hearing loss. I have mixed feelings about making it more
complicated for you. So, let’s just keep it to the basics. If you have hearing loss, there are devices
that will help with audibility and clarity of speech. These devices are recommended depending on
your hearing loss type and degree. It may be overwhelming to research these systems
on your own, so it’s highly recommended to visit your audiologist at Northern Illinois
University to speak about all potential options.

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