Why have a hearing test?
There are many reasons to have a hearing test. The most obvious is a self-referral, when a hearing loss is suspected and a hearing test is needed to confirm the suspicion. Others need hearing tests as part of their employment if working in environments which may be hazardous to hearing. Others will be referred to an Audiologist by a Doctor to investigate symptoms, prior certain medical treatments begin such as chemotherapy, or to obtain a baseline hearing test result before seeing an Ear, Nose and Throat specialist.
An Audiologist will conduct a series of hearing tests to determine the nature and extent of the hearing loss. Accurately understanding hearing test results is important. It will help you understand why you are having trouble in certain situations, such as having difficulty in a noisy environment while hearing well in one on one conversations. Alternatively, you may find that you can hear words but often misunderstand what is said. Understanding your hearing test results will make it easier to understand any recommendations made by your Audiologist, as well as improving your understanding on what your Audiologist is aiming to achieve with hearing aids.
Pure tone Audiometry
Pure tone Audiometry is the main test used to assess hearing. This is a behavioural measure and relies on a patient responding (usually by pressing a button) to a series of tones varying in intensity and pitch. The softest sound that can be heard at each pitch or frequency tested is then depicted on a graph known as an Audiogram.
How to read an Audiogram
An Audiogram is basically a visual representation of your hearing ability. Across the top of the audiogram are the different frequencies (or pitches) from a low frequency at the left side of the audiogram, becoming increasingly high frequency across to the right side. Frequencies are measured in Hertz (Hz).
Down the left side of the audiogram is the sound level, which is measured in decibels (dB). Which ranges from very soft at the top of the graph to very loud at the bottom.
The responses recorded on the graph are the softest tones that can be heard at each frequency. The right ear is recorded as O and the left as X.
The Audiogram will also have other symbols to indicate how well you hear through bone conduction (a part of testing which bypasses the middle ear, which instead sends vibrations to the inner ear). These hearing test results are used by the Audiologist to determine the nature of the hearing loss.
The loss can be sensorineural, meaning it is a permanent loss caused by damage to the inner ear. Or it can be conductive, caused by damage to the outer or middle ear. A conductive loss when treated, can in some circumstances result in hearing being improved or completely restored.
The closer to the top of the graph, the better the hearing is. The closer to the bottom of the graph, the greater the hearing loss.
An Audiogram often has horizontal sections identified to help explain the results.
The top section from -10dB to 20dB represents normal hearing.
The second section from 20dB to 40dB represents a mild hearing loss.
The third section from 40dB to 70dB represents a moderate hearing loss.
The fourth section from 70dB to 90dB represents a severe hearing loss and the final section from 90dB+ represents a profound hearing loss.
Word recognition testing
Testing is conducted to test your brain’s ability to understand words and to determine the optimum performance i.e. what is the best-case scenario with adequate volume?
Tympanometry
Tympanometry is a test of middle ear function. By testing the mobility of the eardrum and middle ear structures, information can be obtained which can help in the diagnosis of middle ear problems.
Acoustic Reflexes
Acoustic reflex testing measures the contraction of a small muscle in the ear in response to a sound stimulus. This provides information which, when combined with other test results, can contribute to a diagnosis.
Interpreting the Audiogram
You now understand the hearing test and know how to read the Audiogram but what does that really mean?
- Is there hearing loss present? If all the symbols on your audiogram ( [/], O/X) are in the top section of the graph (-10dB to 20dB), there is no hearing loss present.
- If some or all the symbols are in the other sections, there is hearing loss present and your Audiologist will discuss whether you would benefit from a hearing aid or further investigation.
- If the bone conduction scores (</> [/]) are better than your air conduction scores (O/X) then you have a conductive hearing loss and your Audiologist would advise further investigation.
It is important to realise that hearing losses are rarely “flat”. Quite often the pattern is sloping, with the low frequencies being in the normal range and the middle and high frequencies sloping to a mild or moderate loss. The hearing difficulties that are noticed in daily life relate to the specific frequencies that are affected by an individual’s hearing loss.
Sometimes speech sounds and common environmental noises are shown on the audiogram, indicating their frequency and decibel level and giving a clear visual representation of which sound you can hear and which you miss.
What next?
It is now time to use the information gained at the hearing test to understand how a hearing loss is impacting your life and how to manage it.
The most common pattern of hearing loss is a sloping high frequency hearing loss. Often the low frequencies are at normal or close to normal levels which means that you can hear quite well. However, because there is hearing loss present in the higher frequencies, the consonants may not be heard. Consonants give clarity to speech so this explains the common complaint “I can hear, I just can’t understand” or “I can hear people speaking but they seem to be mumbling”. If the loss is mild, the brain can fill in the gaps and hearing loss may not even be noticed. However as the loss progresses, listening can become exhausting and can negatively impact on daily communication and socialisation.
At Attune, an Audiologist will inform you if the loss is aidable and it is then time for action! There are a large number of options available in terms of hearing aids and listening devices and your Audiologist can help you to find an option that suits you and your individual lifestyle and circumstances.
The early fitting of hearing aids often means an easier adjustment, as the brain only needs to adapt to a small increase in volume. Hearing aids are programmed to suit your individual pattern of hearing loss, they are discreet and highly effective. To better understand changes in your hearing, book a hearing test with Attune today. Why miss out on anything if you don’t have to!