Audiograms, and How to Read Them
Audiograms are visual graphs with plotted points, which is how audiologists evaluate hearing, and they can be full of useful information, but can often be confusing to try and read, as they contain lots of technical terminology.
The graph itself holds important information, the Y axis showing the Decibel, or volume, of sound tested, while the X axis shows the Frequency, or the pitch of the sound tested.
It's not uncommon to see a shaded area on the Audiogram, before any information is logged. That is commonly referred to as the Speech Banana, as it contains all the sounds necessary for human speech. You can also find Audiograms with pictures and letters covering it, and each picture is located at the pitch and volume it typically resides in real life. |
People like to categorize what level of hearing is shown on an Audiogram, so it's not atypical to see an Audiogram with labeled bands like the above.
However, hearing is hardly a straight line across like the bands, so it's important to not rely on those labels alone. Residual hearing is the hearing that a Deaf or Hard of Hearing person has regardless of loss in other areas. |
Audiograms are covered with different symbols that represent very specific things, so each chart can hold as much information as possible. Each chart has a key, to show what symbol means what.
- Air Conduction
- This is when the sound is put through headphones or speakers that go through the ear naturally.
- Bone Conduction
- This is when the sound is channeled through the Mastoid Bone, the segment of skull directly behind the ear, and bypasses the middle ear to the Cochlea.
- Masking
- This is where the Audiologist will play white noise, often in the opposing ear.
- No Response
- No response to the stimulus.
ETIOLOGIES
There are a multitude of reasons for hearing loss, and there are three main types
SENSORINEURAL
This type affects the Cochlea, vestibulocochlear, (auditory), nerve, or another neural component. EXAMPLES INCLUDE
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CONDUCTIVE
This type affects the Middle ear, preventing sound from reaching the inner ear. EXAMPLES INCLUDE
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MIXED
This type is a combination of both Sensorineural and Conductive types of loss. EXAMPLES INCLUDE
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On an audiogram, those different methods of transmitting sound can illustrate what's happening inside the ear. For example;
In this Audiogram, both Bone Conduction and Air Conduction show the same, decreased, level of hearing, which means that the patient has Sensorineural Hearing Loss
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In this Audiogram, the Air conduction is low, but the Bone conduction is up in "Normal" hearing, which means that the patient has Conductive Hearing Loss
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In this Audiogram, the Air Conduction is in greatly decreased, and the Bone Conduction is higher, but not in the "Normal" band, which means that the patient has Mixed Hearing Loss
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As you can see, there are a myriad of hearing loss types, and one should avoid assumptions. Each individual's hearing is unique, which means that there are many types of amplification if an individual would prefer to amplify.
There are still six categories of hearing loss that can affect language development and education
Unilateral means that the hearing loss is limited to one ear
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Bilateral means that both ears are affected
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Congenital means that it was present at birth
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Adventitious means that it occurred sometime after birth
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Prelingual means that it occurred before the age of 3, as that is an important window in language development
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Postlingual means that the loss occurred after the age of three and the patient has that foundation already
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Causes of hearing loss can sometimes affect other senses, such as a middle and inner ear deformity can affect the semicircular canals, which controls bodies balance. Ushers Syndrome affects both the ears and eyes, leading to some of the Deaf-Blind population. It's not uncommon to have D/HH people with multiple disabilities compounded, from mobility issues, to learning disabilities, it's important to take all disabilities into consideration when looking at amplification, language modes, and classroom placements.