After any hearing test you will be sent a copy of your results. Most people don’t know how to make sense of these, so here is quick guide to give you more understanding. Of course it is always important to follow up with your hearing care professional to discuss any recommendations.
An example of an audiogram showing normal hearing is shown below.
The red line with red circles refers to the right ear, and the blue line with blue crosses the left ear.
The left-hand side of the chart shows the loudness of sound in decibels (dB) with reference to normal hearing in adults.
The higher up the chart the red or blue lines are, the better the hearing is with normal hearing above the 20dB line on the left of the chart.
Moving across the chart from left to right, lower frequencies are on the left and higher on the right. Frequencies are measured in Hertz (Hz) and shown on the chart as Kilo-Hertz (kHz). Middle C on a piano is around 250 Hz (0.25 kHz).
The audiogram therefore shows how well you hear across a range of frequencies.
In this example, a yellow smear showing speech sounds is super-imposed onto the audiogram. Any sounds that are below the red and blue lines will be heard – the closer to the lines, the softer they will be.
Any hearing thresholds at 20 dB or below are considered to show a hearing loss – the lower the lines, the greater the degree of hearing loss.
The British Society of Audiology defines degree of hearing loss as follows:
Normal hearing: You can hear quiet sounds of less than 20 dB
Mild hearing loss: Hearing loss between 20 – 40 dB (typically you might find that you have difficulty following speech in noisy situations).
Moderate hearing loss: Hearing loss between 41 – 70 dB (you will probably find that you have difficulty following speech)
Severe hearing loss: Hearing loss between 71 – 95 dB (you will have severe difficulty following speech without a hearing aid)
Profound hearing loss: Hearing loss over 95 dB (you may have need of hearing aids, cochlear implants, sign language and lip-reading)
An example of a typical age-related hearing loss is shown below.
You can now see red and blue triangles – these are unmasked bone conduction thresholds. The air and bone conduction thresholds are close together, showing that the hearing loss is sensorineural.
In this example the yellow smear showing speech sounds is again super-imposed onto the audiogram. Any sounds that are below the red and blue lines will be heard – the closer to the lines, the softer they will be – but any sounds above the red and blue lines will not be heard unless significantly louder than normal. So lower frequency sounds will be heard relatively well, but mid to high frequency sounds will be heard as very soft, or not at all.
Hearing losses come in all shapes and sizes, and an example of a typical hearing loss associated with middle ear fluid is shown below.
The air conduction thresholds in the left ear shows normal hearing. However, air conduction thresholds show moderate hearing loss in the right ear. The hearing loss is conductive, because masked bone conduction thresholds (the [ symbol) are normal, and there is a big gap between air and bone conduction thresholds.
This type of hearing loss is typical of so-called glue ear, where sticky fluid accumulates in the middle ear, reducing sound transmission to the inner ear. This type of hearing loss is relatively common in young children and is sometimes treated with grommets.
Hearing aids can be very effective in helping with the hearing loss until the glue ear resolves. For further information please see Children’s hearing assessment & management.
What do these results mean in real life?
Mid to high frequency speech sounds provide most of the meaning of speech as they provide clarity and discrimination between similar sounding words, for example /CAT/ /SAT/ and /THAT/ or /TREE/ and /THREE/.
If you don’t hear these sounds so well, then words all mush together, and speech sounds blurred, muffled and unclear. In noisy or echoey environments lower frequency background noise sounds easily overwhelm the softer mid to high frequency sounds masking them out. This is why most people hear better in quiet than they do in noise, and a hearing loss makes hearing in noise even more difficult for people with a hearing loss.
Lower frequency speech sounds provide the volume of sound. Therefore, if you are missing these sounds, speech can appear to be much softer than normal.
How do hearing aids help?
Hearing aids are very carefully programmed to compensate for your hearing loss, and the response at each frequency is calculated based on your audiogram. They can be re-programmed should your hearing loss change.
As well as compensating for loss of volume, they have several signal processing algorithms that provide maximum suppression of background noise and enhance speech so that you can hear as clearly as possible in even the most difficult of environments.
Whatever hearing aid you choose, the first step is to get a complete hearing test done.