If you have ever had a hearing test, the word "audiogram" probably rings a bell; if not, you are not alone. An audiogram is a test that assesses your ability to hear.
The results of an audiogram are presented in the form of a graph and, if you do not know how to read them, it can look like hieroglyphics. Your hearing care professional can help you understand them, but knowing how to interpret them yourself gives you more control over your own follow-up.
Here is everything you need to know about the audiogram, how to interpret its results, and what it reveals about your hearing.
Audiometry
To understand the results of an audiogram, it is important to know how the examination as a whole is conducted and what data is collected during the test.
Find out below how an audiometer works and how the test is performed.
How does an audiometer work?
An audiometer is the device used to perform a hearing test. It consists of headphones worn by the patient, a computer capable of generating sound signals of varying intensities and frequencies, and a control console operated by the practitioner.
The principle of the audiometer is quite simple. The hearing care professional has you wear the headphones and plays a series of sounds at different tones and varying volumes. As the patient, your role is to raise your hand on the side where you hear the sound. If you hear a sound in your right ear, you raise your right hand, and vice versa.
The hearing care professional notes your response to each sound played. If a sound is emitted but not heard by the patient, this is recorded and highlights a gap in your hearing. With an audiometer, not all sounds are necessarily perceptible. That is why the order is generally random, in order to optimize the reliability of the test.
Where is the test performed?
An essential aspect of audiometry concerns the location where the examination is administered. Audiometry requires precise environmental conditions, and the most important is the absence of background noise. If you take a hearing test at a hearing care professional's office, they will likely have a dedicated quiet room, the walls of which are covered with sound-absorbing materials. This eliminates competing external noises.
The main reason why a quiet environment is essential is that the audiometry test evaluates your hearing as close as possible to its minimum threshold. External noise could make the weakest sounds difficult to perceive, or even lead to false responses from the patient. A room that is as quiet as possible reduces the risks of parasitic variables and ensures that the test faithfully reflects your hearing capabilities.
Who performs an audiometry exam?
Many healthcare professionals can contribute to assessing your hearing, but the person who generally performs the audiometry exam is the hearing care professional. They are a healthcare professional holding a degree in audiology (AuD).
The training of a hearing care professional includes a four-year postgraduate program, during which they study the functioning of the ear, ear disorders, and diagnostic methods for identifying the underlying causes of hearing and ear conditions.
How to read an audiogram
During an audiometry exam, a large amount of data is collected, and simply observing a series of frequencies and intensities is not a very clear visual tool for assessing the degree of progression of hearing loss.
This is why, at the end of the test, the data is converted into a line graph. This graph visually shows which sounds are difficult to hear and in which ear.
Here is a detailed examination of the different elements of the graph, to help you better understand and read an audiogram.
The horizontal axis of the graph
The horizontal axis of the graph is generally labeled "frequency" or displays a series of numbers followed by the unit hertz (Hz). Scientifically, the hertz is a unit of frequency: it corresponds to the number of sound waves that pass through a fixed point in one second. While this may not mean much to you, it is actually the scientific way of expressing the pitch of a sound.
As you move across the graph from left to right, the value in hertz increases. In terms of pitch, this means that low-pitched sounds are located more to the left of the graph, while high-pitched sounds are found further to the right.
During an audiometry test, the frequencies tested generally range from 250 Hz to 8000 Hz. This covers the majority of pitches perceptible to humans — what is known as the critical hearing range.
The vertical axis of the graph
The vertical axis of an audiogram is generally labeled "hearing threshold," expressed in decibels (dB). The decibel measures sound intensity: it is a quantifiable way of expressing volume. Your hearing threshold corresponds to the faintest sound you can hear, and it is this value that is plotted on the audiogram graph.
On a standard audiogram, the weakest sounds have a low dB level and are located toward the top of the graph, while louder sounds, with higher dB levels, are found further down.
The graph legend
The legend of a graph gathers information that helps clarify certain aspects of the data series. During an audiometry test, each of your two ears is evaluated separately.
To plot these values, one could create two separate graphs illustrating the hearing capabilities of each ear. But it is often much simpler to merge the two and superimpose the results on the same graph.
To distinguish the results of one ear from those of the other, a legend is almost always used. It tells you which curve corresponds to which ear. This is important, because it makes it possible to see if one ear is more affected than the other and to understand which one poses the most difficulty.
Interpreting the results
Now that you know the different elements of the graph, you can put the pieces of the puzzle together and interpret your own audiogram. In most cases, the audiogram given to patients includes predefined zones extending across the width of the graph and indicating the degree of hearing loss.
On the graph, high-pitched sounds are located further to the right, and the further a data point drops, the more the ability to hear that pitch is reduced.
Perfectly intact hearing has a hearing threshold of less than 20 dB for all sound pitches and forms almost a straight line. Slight variations are possible, but the general trend remains a horizontal line.
In the event of unilateral hearing loss, you will most likely see two distinct curves and marked differences between the hearing capabilities of your two ears. One ear may have totally intact hearing while the other has a much higher threshold, meaning it hears much less well.
Another common profile that you may observe on an audiogram if you are older: normal hearing for low-pitched sounds but a reduced ability to hear high-pitched sounds. This downward-sloping graph can be a sign of a condition called presbycusis, also known as age-related hearing loss.
Hearing aids
Knowing how to read an audiogram also allows you to better understand how hearing aids work. If the audiogram highlights hearing loss, the hearing care professional may recommend a fitting.
Hearing aids are essentially devices that pick up incoming sounds and increase their intensity so that they exceed your hearing threshold. Some hearing aids can even be programmed to amplify only sounds of certain pitches.
Prescription-programmable hearing aids are convenient, but they can be very expensive and require frequent check-ups and adjustments at a hearing care professional's office. For the vast majority of people, over-the-counter hearing aids work just as well and provide the same level of satisfaction.
If you are looking for hearing aids, discover the CLARIA range of hearing aids. With models suitable for almost every budget and a money-back guarantee, you can buy with confidence.
Deciphering the results
In summary, an audiogram can seem intimidating the first time, but once you understand its various elements, interpreting the results becomes much simpler. We hope this guide has provided you with the keys to better understand your hearing and feel more in control of your health.
Sources
Hearing Screening Overview | Minnesota Department of Health
Audiometry screening and interpretation | NCBI
Audiometry - Clinical Methods | NCBI Bookshelf
