An audiogram is a graph of results from an audiometer hearing test. An audiometer is a piece of electronic equipment that creates a series of tones played through headphones. A person’s audiogram visualizes their audiometer test results, displaying hearing thresholds for various frequencies.
This article discusses what an audiogram shows, what the symbols mean, what doctors consider a normal range, and what a person might do next after receiving their audiogram.
One of the most fundamental hearing tests is pure tone audiometry. For this test, a hearing professional, or an audiologist, uses an audiometer to generate tones. These tones vary in frequency, or pitch, measured in Hertz (Hz), and volume, measured in decibels (db).
The test assesses a person’s left and right ear separately.
When an audiologist plays a pure tone, or a sound with a single frequency, a person needs to signal when they hear the sound, typically by raising their hand or pressing a button.
An audiologist determines a person’s hearing threshold for various frequencies. The hearing threshold is the softest sound a person can hear at least 50% of the time.
A person needs to wear a headphone and a bone conductor during an audiometer test. These measure a person’s hearing thresholds through air conduction and bone conduction, respectively.
Sometimes, an audiologist may apply a masking noise on the non-test ear to prevent it from participating in the other ear’s test.
Most specialists mask during bone conduction tests. Also, most mask for air conduction tests when thresholds reach 40 db or louder in over-the-ear earphones, or 60 db for in-ear earphones.
An audiogram records a person’s left and right ear’s air and bone conduction threshold.
An audiogram displays various numbers to represent frequencies and intensities. Frequencies are arranged horizontally from left to right. The range is from low pitch (125 Hz) to high pitch (8000 Hz).
Volume is arranged vertically from top to bottom and ranges from very soft (0 db) to very loud (120 db).
Below are the specific symbols a person may see in an audiogram, along with their meaning:
- X: left air conduction threshold
- O: right air conduction threshold
- >: left unmasked bone conduction threshold
- <: right unmasked bone conduction threshold
- ]: left masked bone conduction threshold
- [: right unmasked bone conduction threshold
Symbols for the left ear are typically in blue, while symbols for the right ear are generally in red.
An audiologist can explain the symbols and how to read an audiogram correctly.
People can check their audiogram results to know whether they have hearing loss, as well as its type and severity. Generally, the farther the results are from the normal hearing range, the greater the hearing loss a person has.
The
| Extent of hearing loss | Thresholds (db) |
|---|---|
| normal hearing | 0–25 db |
| mild hearing loss | 26–40 db |
| moderate hearing loss | 41–55 db |
| moderately severe hearing loss | 56–70 db |
| severe hearing loss | 71–90 db |
| profound hearing loss | 90 db and above |
An audiologist should discuss a person’s results in detail, including explaining whether the person has any degree of hearing loss and how to use the results when making healthcare decisions.
An audiologist will use a person’s test results to determine whether they have hearing loss, as well as its type and severity.
In addition to pure tone audiometry, an audiologist may conduct a speech test or other hearing tests, including:
- tympanometry
- electrocochleography
- auditory brainstem response testing
These will determine the functioning of hearing structures, such as the eardrum, inner ear, and outer ear, and the brain’s response to sound.
Audiograms and other test results can help an audiologist recommend the best hearing solutions for an individual.
A person’s hearing threshold indicated by the audiogram can help determine the amplification necessary when using a hearing aid.
The audiologist will also send results to the person’s referring physician, who can further discuss with the person their results and treatment options.
The World Health Organization (WHO) reports that more than
Treatments and interventions for hearing loss depend on proper assessment and evaluation. According to the
- using technology, such as hearing aids
- considering surgery, such as cochlear and auditory brain stem implants
- joining support groups
- learning sign language and lip-reading
- undergoing habilitation or rehabilitation programs
Specific technologies may be particularly useful for certain types of hearing loss. For example, people with conductive hearing loss might benefit from bone conduction hearing aids or bone-anchored hearing systems.
Also, people with sensorineural hearing loss may benefit from hearing aids or cochlear implants, depending on the severity of the condition. Learn more about types of hearing aids here.
The American Speech-Language-Hearing Association states that the health risks of using inappropriate over-the-counter hearing aids include worsening hearing loss and ear damage.
A hearing professional should work with a person to choose hearing treatment and intervention that is appropriate for their type of hearing loss.
An audiogram is an essential component of hearing tests, as it contains vital information about a person’s hearing capacities and possible hearing loss.
Having an audiogram is necessary for determining the appropriate approach and treatment for a person with hearing problems.