What is an Audiogram?

An audiogram is a graph that displays hearing test results (see an example below). This graph indicates the softest sound someone can hear across the main speech frequencies (low, mid and high pitch sounds). Where the results fall on the audiogram reflects which speech and environmental sounds, if any, aren’t being heard well – or at all.

If you or someone you know has had their hearing tested, you might have seen a chart like this:

How is an audiogram done?

An audiogram is produced following a pure tone audiometry assessment. This type of test establishes the softest sounds you can hear are over a range of pitches. Part of this test is done using "air conduction", which involves wearing headphones or earphones. A sound will be played through the headphones to test how well sound travels to the middle ear via the ear canal. The test also uses bone conduction, which is done by wearing a band across the head with a small vibrating device that sits behind the ear. The focus of bone conduction testing is to see how well sound is received when going through the bone to the cochlea in the inner ear.

During the hearing test, the audiologist will ask you to indicate when you hear sounds, for example you might click a button or raise your hand. Based off what you've indicated you can hear, your results are then plotted onto an audiogram graph.

Speech discrimination is measured by you listening to and repeating recorded words or sentences. This helps identify the degrees of hearing loss, and how much communication difficulty a person is experiencing.

What does an audiogram test for?

An audiometry assessment, which produces audiogram results, is a non-invasive hearing test. The aim of this hearing test is to measure someone’s hearing ability and the sounds, pitches or frequencies they can hear across the frequency range. This assessment can help determine if hearing technology, such as hearing aids, could be beneficial.

What are the different types of hearing loss an audiogram will measure?

An audiogram will help identify not only if someone has a hearing loss, but the type of hearing loss they have. Knowing if the hearing loss is conductive, sensorineural or mixed as well as whether the hearing loss is in the left ear, right ear or both helps inform what treatment options are best.

Conductive hearing loss

Conductive hearing loss occurs when sound waves are unable to carry through the outer or middle ear to the inner ear. For example, earwax or foreign objects might be blocking the ear canal and preventing the sound from traveling to the inner ear. If the middle ear is affected by fluid or infection this can also have an impact on hearing, alternatively, if the eardrum is injured this might also result in hearing loss.

Sensorineural hearing loss

This is one of the most common types of hearing loss, it occurs when the hearing nerve or inner ear become damaged. Often the cause is damaged hair cells in the cochlea. This type of hearing loss can be due to excessive noise exposure, aging, injury, disease or it can be an inherited genetic condition.

Mixed hearing loss

Mixed hearing loss is when someone has a combination of both conductive and sensorineural hearing loss. In these cases, there is damage to both the outer and inner ear.

How long does an audiogram take?

A full hearing test, involving a series of non-invasive assessments, typically takes around 60 to 90 minutes. During this time, a hearing and health history is also taken, as well as discussion about lifestyle and communication goals.

How do you read an audiogram?

At the top of the graph, the numbers ranging from 250 to 12,000 hertz (Hz) represent sound frequencies, from low pitch across to high pitch – similar to the keys on a piano. Most speech is within the range of 250 to 6,000Hz, with consonant sounds such as /S/, /SH/, /CH/ and /T/ among the highest frequencies and vowel sounds amid the lowest.

Along the vertical side, the hearing levels of -10 to 120 measure how loud a sound is in decibels (dB). The normal range of hearing is 20dB or lower, which generally means that the higher up the chart your results are plotted, the better you’re hearing. For example, a bird chirping is typically between 60 and 70dB.

Each ear is plotted as two separate lines on your audiogram. A cross symbol represents your left ear thresholds, while a round circle symbol represents your right ear.

Testing your hearing at different frequencies and volumes enables your audiologist to determine how loud a sound needs to be before you can hear it. For many people identified with hearing loss, assistive technology such as hearing aids can help to bridge those missing sounds.

What does normal hearing look like on an audiogram?

To create an audiogram, an audiologist will ask you to respond to a series of different tones within a quiet listening environment, typically using headphones or insert earphones

Each frequency tone is first played at a volume you can easily hear, with the decibels slowly decreased and increased, a process called “threshold seeking”. This results in your hearing threshold established for each frequency and in both ears, to give an overall picture of your hearing ability.

If hearing is between -10 and 20dB, this is considered normal for most adults, a mild loss is about 20 to 40dB higher than normal and a profound loss is another above 90dB.

Who should get an audiogram?

If you are worried about your hearing or suspect you have a hearing loss, a hearing test is recommended. Here are some common symptoms of hearing loss:

Regularly asking people to repeat themselves
A ringing or buzzing in your ears (tinnitus)
Phone conversations are difficult
Constantly turning the volume up on the TV or radio
It’s hard to have conversations when there is background noise, for example at a noisy cafe

What’s next?

Following a hearing test, your audiologist will talk you through your hearing level results including any hearing loss identified.

For people who require hearing aids, an audiogram helps the audiologist to determine which sounds can’t be heard and to ensure the hearing aids are programmed to focus on increasing the audibility of these sounds.

Hear and Say provides an array of audiology services for people of all ages, including comprehensive hearing tests, hearing aid fitting and management, tinnitus assessments and hearing implant services.