Understanding Audiograms: A Guide to Your Hearing Test Results
An audiogram is a graph that provides a detailed picture of your hearing ability. It's the primary tool audiologists use to assess and diagnose hearing loss. Understanding your audiogram can empower you to take a more active role in managing your hearing health. This guide will walk you through the different components of an audiogram, explain what they mean, and help you understand how to use this information to inform your treatment options.
What is an Audiogram?
An audiogram is a visual representation of your hearing test results. It plots the softest sounds you can hear at different frequencies. The test is usually conducted in a soundproof booth using headphones. During the test, you'll be asked to respond (usually by raising your hand or pressing a button) when you hear a tone. The audiologist records the quietest sound you can hear at each frequency, and these results are plotted on the audiogram.
The audiogram provides valuable information about:
The degree of hearing loss: How mild, moderate, severe, or profound your hearing loss is.
The type of hearing loss: Whether the problem lies in the outer, middle, or inner ear (or a combination).
The frequencies affected: Which pitches (high, low, or all) are most difficult for you to hear.
This information is crucial for determining the best course of action for managing your hearing loss, which may include hearing aids, assistive listening devices, or other interventions. learn more about Hearing and our services.
Decibels (dB) and Hertz (Hz)
To understand an audiogram, you need to grasp the concepts of decibels (dB) and hertz (Hz).
Decibels (dB): Decibels measure the intensity or loudness of a sound. On the audiogram, decibels are represented on the vertical axis. The top of the audiogram represents softer sounds (0 dB), while the bottom represents louder sounds (100+ dB). A higher decibel level means a louder sound. For example, a whisper might be around 30 dB, while a normal conversation is around 60 dB. Sounds above 85 dB can be harmful to your hearing over prolonged exposure.
Hertz (Hz): Hertz measure the frequency or pitch of a sound. On the audiogram, hertz are represented on the horizontal axis. The left side of the audiogram represents lower frequencies (like the rumble of a truck), while the right side represents higher frequencies (like the chirping of a bird). The range of frequencies typically tested in an audiogram is 250 Hz to 8000 Hz, which covers the range of human speech.
Think of it this way: dB is about how loud the sound is, and Hz is about how high or low the sound is. A healthy ear can hear a wide range of both frequencies and decibel levels.
Interpreting the Symbols and Lines
Audiograms use specific symbols to represent your hearing thresholds – the quietest sounds you can hear – at each frequency. Here's a breakdown of the common symbols:
O (Red Circle): Represents the hearing threshold for your right ear using air conduction. Air conduction tests the entire auditory system, from the outer ear to the brain.
X (Blue X): Represents the hearing threshold for your left ear using air conduction.
< (Red): Represents the hearing threshold for your right ear using bone conduction. Bone conduction bypasses the outer and middle ear and directly stimulates the inner ear.
> (Blue): Represents the hearing threshold for your left ear using bone conduction.
What do the lines mean?
After the hearing test, the audiologist will connect the symbols for each ear with lines. These lines represent your hearing thresholds across the tested frequencies. The lower the line on the audiogram, the poorer your hearing is at that frequency. For example, if the line for your right ear is at 40 dB at 1000 Hz, it means you need a sound of at least 40 dB to hear a 1000 Hz tone in your right ear.
Normal Hearing:
Normal hearing is generally considered to be within 0-25 dBHL (decibel Hearing Level) across all frequencies. This means that a person with normal hearing can hear very soft sounds.
Understanding Different Types of Hearing Loss on an Audiogram
An audiogram can help identify the type of hearing loss you have. There are three main types:
Conductive Hearing Loss: This type of hearing loss occurs when sound is blocked from reaching the inner ear. This can be due to a problem in the outer or middle ear, such as earwax blockage, fluid in the middle ear, or a damaged eardrum. On an audiogram, conductive hearing loss is characterised by a difference between the air conduction and bone conduction thresholds. The bone conduction thresholds will be better (lower) than the air conduction thresholds.
Sensorineural Hearing Loss: This type of hearing loss occurs when there is damage to the inner ear (cochlea) or the auditory nerve. This can be caused by aging, noise exposure, genetics, or certain medications. On an audiogram, sensorineural hearing loss is characterised by air and bone conduction thresholds being similar and both showing hearing loss.
Mixed Hearing Loss: This type of hearing loss is a combination of conductive and sensorineural hearing loss. There is a problem in both the outer or middle ear and the inner ear or auditory nerve. On an audiogram, mixed hearing loss is characterised by a difference between the air and bone conduction thresholds, with both showing hearing loss.
Examples:
Conductive Hearing Loss Example: Imagine your air conduction thresholds are around 40-50 dB, while your bone conduction thresholds are around 10-20 dB. This suggests a problem in the outer or middle ear preventing sound from efficiently reaching the inner ear.
Sensorineural Hearing Loss Example: Imagine both your air and bone conduction thresholds are around 50-60 dB across all frequencies. This suggests damage to the inner ear or auditory nerve.
Mixed Hearing Loss Example: Imagine your air conduction thresholds are around 60-70 dB, while your bone conduction thresholds are around 40-50 dB. This indicates a problem in both the outer/middle ear and the inner ear/auditory nerve.
Understanding the type of hearing loss is crucial for determining the appropriate treatment options. frequently asked questions can help clarify any initial concerns.
Using Your Audiogram to Inform Treatment Options
Your audiogram is a valuable tool for informing treatment options for your hearing loss. Based on the degree, type, and frequencies affected, your audiologist can recommend the most appropriate course of action.
Here are some common treatment options:
Hearing Aids: Hearing aids are electronic devices that amplify sound to make it easier to hear. They are the most common treatment option for sensorineural hearing loss. Modern hearing aids are highly sophisticated and can be programmed to address your specific hearing needs. Your audiogram helps the audiologist program the hearing aids to amplify the frequencies where you have the most difficulty hearing.
Assistive Listening Devices (ALDs): ALDs are devices that help you hear in specific situations, such as in a noisy restaurant or while watching television. Examples include FM systems, infrared systems, and induction loop systems.
Medical Treatment: For conductive hearing loss, medical treatment may be an option. This could include removing earwax, treating an ear infection, or surgery to repair a damaged eardrum or middle ear bones.
Cochlear Implants: Cochlear implants are electronic devices that are surgically implanted into the inner ear. They bypass the damaged parts of the inner ear and directly stimulate the auditory nerve. Cochlear implants are typically used for people with severe to profound sensorineural hearing loss who do not benefit from hearing aids.
Communication Strategies: Learning communication strategies can help you better understand speech in challenging listening situations. These strategies include asking people to speak clearly, facing the speaker, and reducing background noise.
Your audiologist will use your audiogram, along with other factors such as your lifestyle and communication needs, to develop a personalised treatment plan. It's important to discuss your concerns and goals with your audiologist to ensure that you receive the best possible care. The audiogram is the starting point for improving your hearing and quality of life. When choosing a provider, consider what Hearing offers and how it aligns with your needs.