You have just completed your hearing test. The hearing specialist is now entering the room and presents you with a chart, like the one above, except that it has all of these signs, colors, and lines. This is designed 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 complexity at a time when you’re supposed to be concentrating on how to enhance your hearing. But don’t let it mislead you — just because the audiogram looks perplexing doesn’t mean that it’s difficult to understand.

After looking through this article, and with a little vocabulary and a few basic concepts, you’ll be reading audiograms like a pro, so that you can concentrate on what actually matters: healthier hearing.

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

Understanding Sound Frequencies and Decibels

The audiogram is essentially just a graph 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 fundamental level it’s just a chart graphing two variables, as follows:

The vertical axis records 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 go down the line, the decibel levels increase, standing for steadily 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 keep moving along the horizontal axis to the right, the frequency will gradually increase until it arrives at 8,000 Hz. Vowel sounds of speech are typically low frequency sounds, while consonant sounds of speech are high frequency sounds.

And so, if you were to begin 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 (switching from vowel sounds to consonant sounds) while increasing the volume of sound (moving from fainter to louder volume).

Examining Hearing and Marking Up the Audiogram

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

Easy. Start 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, beginning with the smallest volume decibel level. If you can perceive it at the lowest level (0 decibels), a mark is made at the crossroad of 125 Hz and 0 decibels. If you can’t perceive the 125 Hz sound at 0 decibels, the sound will be presented again at the next loudest decibel level (10 decibels). If you can hear it at 10 decibels, a mark is created. If not, advance on to 15 decibels, and so on.

This identical tactic is duplicated for every frequency as the hearing specialist proceeds along the horizontal frequency line. A mark is created at the lowest perceivable decibel level you can perceive for every sound frequency.

As for the other symbols? If you observe 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 generally used to mark the points for the left ear; an O is applied for the right ear. You may observe some additional symbols, but these are less crucial for your basic understanding.

What Normal Hearing Looks Like

So what is seen as normal hearing, and what would that look like on the audiogram?

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

Take the blank graph, find 25 decibels on the vertical axis, and draw a horizontal line entirely across. Any mark made underneath this line may reveal hearing loss. If you can hear all frequencies underneath this line (25 decibels or higher), then you more than likely have normal hearing.

If, on the other hand, you cannot perceive the sound of a certain frequency at 0-25 dB, you likely have some kind of hearing loss. The lowest decibel level at which you can perceive sound at that frequency establishes the extent of your hearing loss.

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

As an overview, here are the decibel levels linked with normal hearing along with the levels correlated 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 marks of hearing loss look like? Seeing as the majority of cases of hearing loss are in the higher frequencies (referred to as — you guessed it — high-frequency hearing loss), the audiogram would have a downwards sloping line from the top left corner of the graph slanting downward horizontally to the right.

This indicates that at the higher-frequencies, it requires a progressively louder decibel level for you to perceive the sound. Furthermore, considering that higher-frequency sounds are connected with the consonant sounds of speech, high-frequency hearing loss impairs your ability to grasp and pay attention to conversations.

There are a few other, less widespread patterns of hearing loss that can turn up on the audiogram, but that’s probably too much detail for this entry.

Test Your New Knowledge

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