The Audiogram
What is an audiogram?
An audiogram is a chart with a diagram where graphs representing the two ears show the softest or lowest sound levels (or sound pressures) a person is able to hear at different pitches or frequencies ranging from low frequency to high frequency.
The audiogram illustrates your hearing ability by showing your hearing threshold at the various frequencies. Hearing threshold is an indication of how low the sound level or soft the sound may get before it is inaudible for the person having the test.
How to make an audiogram?
The audiogram is made based on the results of a pure-tone test (also called pure-tone audiometry) where your hearing ability at certain frequencies is tested. The pure-tone test is typically performed by a hearing care professional.
The result from the pure-tone test (pure-tone audiometry) is then presented in the audiogram, typically showing the hearing level at different frequencies on both the left ear and the right ear.
During the hearing test, the results are recorded on the audiogram by means of red Os for the right ear and blue Xs for the left one. The resulting red and blue lines show your hearing threshold for each ear, and the results may well differ from ear to ear.
A pure-tone test and the results of this presented in an audiogram are only a part of a complete professional hearing test.
Interpretation of the audiogram
Based on the audiogram and other tests and examinations, the hearing care professional can tell if you have a hearing loss and if so, determine how serious it is and if you may benefit from using hearing aids or other hearing instruments such as cochlear implants or other hearing implants.
The hearing care professional/audiologist should always explain the results of the audiogram to you, giving you the best possible understanding of your actual hearing status.
An audiogram alone does not identify the type of hearing loss that you might have. It only shows your hearing level. To identify the specific type of hearing loss such as a sensorineural hearing loss or a conductive hearing loss, more examinations and test must be carried out by the hearing professional.
How to read an audiogram?
How do you interpret an audiogram? This is how an interpretation of an audiogram is carried out:
An audiogram has two axes.
The vertical axis of the audiogram represents sound volume or intensity, which is measured in decibels (dB). The more one moves down the axis, the louder the sound becomes. This corresponds to turning up the volume on a radio or TV. Zero decibel (dB) at the top of the axis represents the softest sound (lowest sound pressure) a person is normally able to hear.
The horizontal axis of the audiogram represents sound frequency or pitch measured in Hertz (Hz). Sound frequency increases gradually the further one moves to the right along the axis. The audiogram shows the lowest frequencies on the left side of the audiogram and the highest frequencies to the right.
This movement can be compared to playing on the left side of a piano and gradually moving to the right side where the tone becomes more and more high-pitched. Frequencies between 500 Hz and 3000 Hz are most commonly used during ordinary conversation.
Read more: What is dB and frequency?
What does a normal audiogram look like?
What is a normal audiogram? What does a normal audiogram look like?
In fact, there are no normal audiograms as hearing ability differs from person to person. But in an audiogram that shows “normal hearing”, meaning no hearing loss, the ability to hear the different tones in the test should be under 25 dB at the different frequencies. A hearing threshold of between 0 and 25 dB is typically considered “normal hearing”. If the hearing level (the hearing threshold) is more than 25 dB at the different frequencies, you normally speak of a hearing loss.
Generally speaking, the more markings at 25 dB or more, at frequencies which are normally used in normal conversation, the more difficult it is to hear what is being said. And in situations with a lot of background noise, it will often be even more difficult to hear speech and other sounds properly.