An audiogram is a tool that charts your unique hearing loss. The graph to the right includes images that depict sounds of daily life and are located where those sounds typically fall relative to tone pitch and loudness. The letters therein denote common sounds of speech. Frequency (tone pitch) is measured on the x-axis, while sound intensity (loudness) is measured on the y-axis. The shaded area shows where most common speech sounds occur.
Hearing loss is measured in decibels hearing level (dB HL). The thresholds for different types of hearing loss are as follows:
- Mild: 25–40 dB HL
- Moderate: 41–55 dB HL
- Moderately severe: 56–70 dB HL
- Severe: 71–90 dB HL
- Profound: 90+ dB HL
The most common challenge associated with hearing loss is “understanding” everything that’s being said. Most people can hear loudness of speech sounds fine, but can’t distinguish between some consonants and vowels and so easily lose the meaning of some words.
High-frequency hearing loss is very common in the early onset of overall hearing loss. Many important speech sounds, like the sounds S, F, SH, CH and TH, are distorted by high-frequency hearing loss. Depending on the severity of hearing loss, these speech sounds may be heard, but not understood properly; thus, it is more challenging to participate in conversation. Further, voices of women and children tend to be higher pitched, making them more difficult to understand when one is affected by high-frequency hearing loss.
The softest sounds you hear at each pitch make up your hearing threshold and those thresholds are marked on your audiogram. Typically, the parts of the test given to you through headphones are called 'air' thresholds because the sound must travel through the air of the ear canal to be heard. An O is used for the right ear and an X is used for the left ear to represent your air thresholds.
A bone-conduction vibrator is usually used to test for thresholds as well. A < symbol is used for the right ear and a > symbol is used for the left ear. A bone-conduction vibrator is a device that gently rests on the bone behind the ear and is held in place by a small metal band stretching over the top of the head. This device transmits sound vibrations through the bones and tissue and fluids within the skull directly to the cochlea (the hearing organ of the inner ear). This process allows the examiner to bypass your outside and middle ear areas and test the sensitivity of your inner ear directly.
Hearing Exam Results
By combining the results of these two tests, your hearing healthcare professional can determine your type of hearing loss, how well you hear low, medium and high pitches, and which part of the ear is causing the loss.
If you believe you may be experiencing a hearing loss it is recommended to have your hearing tested as soon as possible. A hearing exam will let you know the status of your hearing health and your hearing healthcare professional will be able to recommend the next steps.