The Audiogram & You

On the audiogram, frequencies or pitches measured in Hertz (Hz) are represented along the horizontal axis. Just like keys on a piano, the low pitched notes are on the left and the high pitched notes are on the right. Even though you can hear more pitches than those shown on the audiogram, these pitches are the ones that are most important for hearing speech.

Loudness levels measured in decibels (dB) are represented along the vertical axis. The number zero (0) represents the softest sound the average, typically hearing 18 year old can hear. As the numbers on the vertical axis increase, so does loudness.

When your audiologist tests your hearing, she or he puts headphones or foam earphones on you and presents a certain pitched sound at a loudness level that you can hear. The audiologist then makes that sound softer and softer until you can just barely hear that sound.  The level at which you can barely hear that sound is your “hearing threshold” for that sound. Your audiologist then records an “O” for “air conduction” thresholds for the right ear and an “X” for “air conduction” thresholds for the left ear. Air conduction refers to how sound starts to travel through your hearing system. In other words, the sound travels from the earphone, through the air, into your ear canal (hole in your ear) and eventually on up to your brain. 

Your audiologist might also place a headband on you that has a little vibrator (bone conductor) that goes behind your ear. The audiologist then follows the same procedure as she or he does when you are wearing earphones.  The audiologist plots a < for “bone conduction” thresholds in your right ear and a > for “bone conduction” thresholds in your left ear. Bone conduction refers to how sound travels from the bone conductor, through your mastoid bone (the bump you feel behind your ear) to your cochlea or inner ear. 

All of these symbols tell the audiologist if there is a hearing issue and if so, where the hearing issue is. If the air conduction thresholds (X or O) are close to the bone conduction thresholds (< or >) on the audiogram, it means that the hearing issue is coming from the cochlea or inner ear. This would be referred to as a “sensorineural” hearing loss. If the bone conduction thresholds are higher on the audiogram than the air conduction thresholds, then the issue is coming from the middle ear or maybe from a lot of wax in the ear canal. This would be called a “conductive” hearing loss. Sometimes the hearing loss can be both sensorineural and conductive and then it is called a “mixed” hearing loss.

Speech sounds are made up of different frequencies (pitches) and loudness.  Sounds like “s” are high pitch and soft, and sounds like “m” are low pitch and loud.  

In order to hear all speech sounds well, the “X”s and “O”s on the audiogram should be somewhere between 0 and 15dB for a young person.  If they are outside this range, then there is hearing loss.  Depending on how much hearing loss there is, it will affect how well you can hear speech. If the “X”s and “O”s fall closely to or below the speech sounds, hearing aids or perhaps a cochlear implant will be required to hear speech.

In the example audiogram below, we can see that the right ear (red circles) can hear several speech sounds (such as “sh”) as the hearing thresholds are above some the speech sounds.  The left ear (blue line) cannot hear several of the speech sounds as the hearing thresholds are below many of the speech sounds (such as “ch”). The good news is all the speech sounds would be heard when wearing hearing aids.

You may have heard the labels, mild, moderate, severe and profound.  These words are used to define how much hearing loss there is.  For those with mild hearing loss, some speech can be heard without hearing aids but the person who is speaking needs to be close to you and in a quiet environment. However, to hear and learn in a classroom setting, hearing aids are needed if you have a mild hearing loss.  For those with moderate and severe hearing loss, hearing aids are required to hear speech in all listening environments. For those with profound hearing loss, a cochlear implant is required to have access to speech.  

As your audiogram is as unique as you are, I encourage you to take a look at your audiogram with your hearing teacher and/or your audiologist.  You may be surprised what you learn.