Audiogram

You’ve just finalized your hearing test. The hearing specialist is now coming into the room and provides you with a chart, like the one above, except that it has all of these signs, colors, and lines. This is supposed to demonstrate to you the exact, mathematically precise characteristics of your hearing loss, but to you it might as well be written in Greek.

The audiogram creates confusion and complication at a time when you’re supposed to be directing your focus on how to enhance your hearing. But don’t let it mislead you — just because the audiogram looks puzzling doesn’t mean that it’s difficult to interpret.

After looking through this article, and with a little terminology and a handful of basic principles, you’ll be reading audiograms like a professional, so that you can concentrate on what actually is important: healthier hearing.

Some advice: as you read the article, reference the above blank audiogram. This will make it easier to comprehend, and we’ll cover all of those cryptic marks the hearing specialist adds later.

Understanding Sound Frequencies and Decibels

The audiogram is essentially just a chart that records sound volume on the vertical axis and sound frequency on the horizontal axis. (are you having flashbacks to high school geometry class yet?) Yes, there’s more to it, but at a basic level it’s just a chart graphing two variables, as follows:

The vertical axis documents sound intensity or volume, measured in decibels (dB). As you move up the axis, the sound volume decreases. So the top line, at 0 decibels, is a very soft, faint sound. As you move down the line, the decibel levels increase, standing for gradually louder sounds until you get to 100 dB.

The horizontal axis records sound frequency, measured in Hertz (Hz). Starting at the top left of the graph, you will see a low frequency of 125 or 250 Hz. As you move along the horizontal axis to the right, the frequency will progressively increase until it gets to 8,000 Hz. Vowel sounds of speech are usually low frequency sounds, while consonant sounds of speech are high frequency sounds.

And so, if you were to start off at the top left corner of the graph and draw a diagonal line to the bottom right corner, you would be increasing the frequency of sound (shifting from vowel sounds to consonant sounds) while increasing the volume of sound (moving from fainter to louder volume).

Testing Hearing and Marking Up the Audiogram

So, what’s with all the markings you usually see on this simple graph?

Easy. Begin at the top left corner of the graph, at the lowest frequency (125 Hz). Your hearing consultant will present you with a sound at this frequency by way of headsets, starting with the smallest volume decibel level. If you can perceive it at the lowest level (0 decibels), a mark is created at the crossroad of 125 Hz and 0 decibels. If you can’t hear the 125 Hz sound at 0 decibels, the sound will be provided once again at the next loudest decibel level (10 decibels). If you can hear it at 10 decibels, a mark is made. If not, advance on to 15 decibels, and so on.

This identical method is reiterated for each frequency as the hearing specialist progresses along the horizontal frequency axis. A mark is made at the lowest perceivable decibel level you can perceive for every sound frequency.

In terms of the other symbols? If you notice two lines, one is for the left ear (the blue line) and one is for the right ear (the red line: red is for right). An X is typically applied to mark the points for the left ear; an O is employed for the right ear. You may see some other characters, but these are less important for your basic understanding.

What Normal Hearing Looks Like

So what is considered to be normal hearing, and what would that look like on the audiogram?

People with regular hearing should be able to perceive each sound frequency level (125 to 8000 Hz) at 0-25 decibels. What might this look like on the audiogram?

Just take the blank graph, locate 25 decibels on the vertical axis, and draw a horizontal line all the way across. Any mark made under this line may demonstrate hearing loss. If you can perceive all frequencies beneath this line (25 decibels or higher), then you most likely have normal hearing.

If, however, you cannot perceive the sound of a specified frequency at 0-25 dB, you very likely have some type of hearing loss. The smallest decibel level at which you can perceive sound at that frequency determines the intensity of your hearing loss.

For example, take the 1,000 Hertz frequency. If you can hear this frequency at 0-25 decibels, you have normal hearing for this frequency. If the smallest decibel level at which you can hear this frequency is 40 decibels, for instance, then you have moderate hearing loss at this frequency.

As a summary, here are the decibel levels associated with normal hearing along with the levels linked with mild, moderate, severe, and profound hearing loss:

Normal hearing: 0-25 dB

Mild hearing loss: 20-40 dB

Moderate hearing loss: 40-70 dB

Severe hearing loss: 70-90 dB

Profound hearing loss: 90+ dB

What Hearing Loss Looks Like

So what would an audiogram with indications of hearing loss look like? Considering that many cases of hearing loss are in the higher frequencies (labeled as — you guessed it — high-frequency hearing loss), the audiogram would have a descending slanting line from the top left corner of the graph slanting downward horizontally to the right.

This signifies that at the higher-frequencies, it takes a increasingly louder decibel level for you to experience the sound. Furthermore, considering that higher-frequency sounds are linked with the consonant sounds of speech, high-frequency hearing loss weakens your ability to understand and pay attention to conversations.

There are other, less common patterns of hearing loss that can appear on the audiogram, but that’s probably too much detail for this article.

Test Your New-Found Knowledge

You now know the nuts and bolts of how to interpret an audiogram. So go ahead, book that hearing test and impress your hearing specialist with your newfound talents. And just think about the look on their face when you tell them all about your high frequency hearing loss before they even say a word.

Why wait? You don't have to live with hearing loss. Call Us Today