Introduction
Hearing loss is an increasingly common condition, affecting people of all ages. According to the World Health Organization, by 2050 nearly 2.5 billion people worldwide suffer from some degree of hearing loss. This number is expected to grow as populations age and noise pollution continues unabated.
The impacts of hearing loss are wide-ranging – it can negatively affect social interactions, learning ability, career performance, and overall quality of life. Fortunately, a variety of hearing tests exist to accurately evaluate hearing ability and determine if medical interventions like hearing aids or cochlear implants may help.
This guide will provide an overview of the main types of hearing tests used by audiologists and ENT doctors.
The right hearing test or combination of tests will depend on your age, symptoms, medical history, and the cause of suspected hearing troubles. Common tests include audiometry to measure hearing sensitivity, tympanometry to assess the middle ear, otoacoustic emissions to evaluate the inner ear, and speech audiometry for word recognition.
Understanding the options available is an important first step to getting your hearing tested and treated. Keep reading to learn about the core hearing tests that may be recommended for your symptoms and situation.
7 Types of Hearing Test Explained
Audiometry
Audiometry is one of the most common hearing tests used to assess hearing ability. It is also known as pure tone audiometry or tone audiometry.
Audiometry tests hearing sensitivity across a range of frequencies that are important for speech comprehension. During a pure tone audiometry test, the audiologist presents tones at various volumes and different pitches and asks the patient to indicate when they can hear the tone. The tones are presented through headphones to one ear at a time using a machine called an audiometer. Your audiologist may also conduct a speech test, where they evaluate your ability to listen to words and repeat them, to further assess your hearing abilities, including the function of the sensory cells in the ear. This is an important part of the audiometry process, as it helps determine your overall hearing health and any potential issues that may need to be addressed, including those related to the outer ear.
The results of the test are plotted on a graph called an audiogram which shows hearing ability at different frequencies and volumes.
Audiogram explained
An audiogram is a key diagnostic tool used to assess an individual’s hearing ability across different frequencies and intensities. The audiogram provides a visual representation of the results, typically in the form of a graph with frequency levels on the horizontal axis and intensity levels on the vertical axis. Understanding an audiogram can help audiologists identify the type and degree of hearing loss a person may be experiencing, guiding them in recommending appropriate treatments or interventions for better hearing health.
Pure tone audiometry can detect several types of hearing loss:
- Conductive hearing loss which involves the outer and middle ear. This type of loss usually affects all frequencies evenly
- Sensorineural hearing loss which relates to the inner ear and/or auditory nerve. This affects certain frequencies more than others
- Mixed hearing loss which is a combination of conductive and sensorineural loss
Audiometry testing is commonly used for:
Routine hearing screening and evaluation
- Diagnosing hearing disorders
- Determining the need for treatment such as hearing aids or cochlear implants
- Monitoring hearing ability over time to track changes
- Pre-employment hearing tests
- Medico-legal purposes
This test provides important baseline information about a person’s hearing abilities across the speech frequencies. It is often the first test conducted when evaluating hearing.
Tympanometry
Tympanometry tests for functionality of the middle ear and mobility of the eardrum. It does this by altering air pressure in the ear canal and measuring how the eardrum responds.
A small probe is placed in the entrance of the ear canal. It will emit tones and sounds at different volumes and air pressures. As the air pressure changes, a microphone inside the probe measures how the sound is transmitted through the middle ear.
The test results are plotted on a graph called a tympanogram, which registers eardrum movement. The shape of the tympanogram indicates how well the eardrum and ossicles (tiny bones) in the middle ear are able to transmit sound. A normal test will show good mobility of the eardrum. However, if the eardrum is stiff or scarred, it won’t move as freely in response to pressure changes, which can indicate conditions such as glue ear. Understanding the results of a tympanometry test is crucial in determining the health of your eardrum and overall hearing ability.
Tympanometry is often used when someone reports issues like:
- Ear pain or discomfort
- Fluid draining from the ear
- Dizziness or balance problems
- A feeling of ear fullness or difficulty hearing
It can identify potential problems such as a perforated eardrum, fluid buildup, ear infections, or issues with the bones in the middle ear. The test only takes a few minutes and is non-invasive.
Along with other hearing tests, it provides important information to diagnose and treat ear and hearing disorders.
Otoacoustic Emissions (OAE) Testing
Otoacoustic emissions (OAE) testing is a simple, non-invasive method to check cochlear function and inner ear health. It measures otoacoustic emissions, which are faint sounds generated by the inner ear when responding to sound stimulation. Checking OAEs can indicate how well outer hair cells in the cochlea are working.
There are two main types of OAE testing:
- Transient Evoked Otoacoustic Emissions (TEOAE). These measure otoacoustic emissions in response to very brief sounds like clicks or tone bursts. Responses are recorded by a small probe inserted into the ear canal. TEOAEs assess outer hair cell function from about 1-4kHz, a key area for speech understanding.
- Distortion Product Otoacoustic Emissions (DPOAE). These measure sound waves produced in response to two close frequencies played into the ear canal. The cochlea generates distortion tones at specific frequencies. Responses indicate function between 1-8kHz, covering a wider high frequency range.
OAE testing is very useful for:
- Screening newborn infants since it doesn’t require a behavioural response. Many countries implement universal newborn hearing screening.
- Monitoring cochlear status for early detection of changes that could indicate ototoxicity or noise damage before hearing loss begins.
- Diagnosing dysfunction of outer hair cells. Absent or reduced emissions can indicate damaged outer hair cells even if behavioural hearing tests are normal.
The OAE test procedure is quick, easy, and painless. The probe seals into the ear canal, then plays very soft tones into the ear while recording resulting emissions.
Since no response is required, OAEs can be measured in infants, younger children, and other difficult to test patients.
The presence of emissions is a good sign showing the cochlea responds properly to sound. Weakened or absent OAEs indicate damaged or impaired outer hair cell function.
OAE testing is an important tool for assessing cochlear and inner ear health.
Speech Audiometry
Speech audiometry evaluates how well you can hear and understand speech. The tests require you to repeat words that are presented at different volumes and against different levels of background noise.
There are several common speech recognition tests:
- Word recognition test. You listen to pre-recorded one-syllable words and report back the words you heard. Words are presented at different volumes to determine your speech reception threshold and word recognition scores at each level.
- Speech-in-noise test. You listen to and repeat sentences that are presented with background noise at different signal-to-noise ratios. This evaluates how well you can understand speech with real-world noise distractions.
- Quick Speech-in-Noise test (QuickSIN). You listen to and repeat sentences with background noise that gradually gets louder. It quickly assesses your ability to understand speech with interfering noise.
Speech audiometry is useful for:
- Testing how well hearing aids help you understand speech.
- Assessing auditory processing disorder – difficulty hearing against background noise despite normal hearing thresholds.
- Identifying inconsistencies that may indicate non-organic hearing loss.
- Monitoring hearing loss progression over time.
Determining if a cochlear implant is a good option for severe hearing loss.
Speech audiometry provides important information about how well you can understand conversational speech, which is different from pure tone hearing tests. The results help hearing specialists recommend appropriate treatments and technologies to improve speech comprehension.
How does a pure-tone audiometry test differ from speech audiometry?
Pure-tone audiometry test measures hearing sensitivity by detecting the faintest sound you can hear at different frequencies. Speech audiometry, on the other hand, assesses how well you understand spoken language by measuring your ability to hear and repeat words of varying volumes.
Acoustic Immittance
Acoustic immittance is a hearing test that assesses the ear’s ability to conduct sound waves through the middle ear. It measures the movement of the eardrum and the tiny bones of the middle ear by creating variations of air pressure in the ear canal.
The test works by placing a soft plug in the entrance of the ear canal. The plug contains a speaker and a microphone and is connected to a computer. The computer then generates different tones and pressures to the ear through the speaker. As the eardrum vibrates in response to the changing pressure, a microphone in the plug measures these vibrations.
Acoustic immittance can detect fluid in the middle ear, mobility or stiffness of the eardrum, and other conditions affecting the conductive pathways of the ear.
It is often used during a standard hearing evaluation and may be ordered if someone is experiencing some forms of hearing loss, ear pressure, dizziness, or other ear-related symptoms.
This relatively quick and non-invasive test provides valuable information about the status of the middle ear.
Auditory Brainstem Response (ABR)
The auditory brainstem response (ABR) test is used to check the brain pathways for hearing. It’s sometimes referred to as a brainstem auditory evoked response (BAER) test.
ABR testing checks the hearing nerve and brain pathways for hearing. Small electrodes will be placed on the head during the test. Clicking noises are played through earphones into one ear at a time while the electrodes record the nerve signals and how the brain responds to sounds.
The ABR test is used to:
- Check hearing in babies or young children
- Check hearing in adults when regular hearing tests can’t be done, like when the patient can’t respond reliably
- Check the hearing nerve and brain pathways in people with certain tumours or neurological conditions
- Find the cause for certain kinds of hearing loss or deafness
- Check hearing function during medical procedures that involve the hearing nerve or inner ear
During ABR testing, the patient may hear clicking sounds or feel sensations during the test. The patient is required to lie still throughout the length of the test, which takes around 15-60 minutes. Young children are often sedated for the ABR test to ensure stillness and accuracy of results.
The ABR test is an important diagnostic tool for detecting the location of hearing loss in the pathways. It can identify if there are issues with the cochlea, hearing nerve, or brain function for interpreting sounds. This helps doctors determine the underlying cause of hearing problems.
Balance Testing
Balance issues that stem from the inner ear can be evaluated using a combination of tests. These help to identify problems with the vestibular system, which is the sensory system responsible for balance and spatial orientation.
The inner ear contains the semicircular canals that detect rotation of the head. It also contains the utricle and saccule organs that sense linear acceleration, like gravity and movement. Together, they provide sensory input to help maintain balance and stance.
Damage to the vestibular system can occur due to ageing, infections, head injuries, or other medical conditions. This can result in chronic dizziness, vertigo, and unsteadiness. Balance testing aims to pinpoint the location and cause of vestibular dysfunction.
During balance testing, a doctor may start with a basic assessment of posture and balance function. They will observe how well a patient can stand steadily with their feet together and eyes closed. The Unterberger test may be used, where the patient marches in place with their eyes closed. Swaying or rotating to one side can indicate a vestibular problem on that side.
Next, eye movements are evaluated for abnormalities that can signify inner ear disorders. Nystagmus, which is an involuntary movement or twitching of the eyes, can suggest the presence of dizziness-causing conditions.
Other tests provide more objective measurements of the vestibular system:
- Videonystagmography (VNG) uses cameras to track eye movements during stimulation of the inner ear. It assesses the function of each semicircular canal
- Rotary chair testing involves sitting in a rotating chair. Eye movements are monitored for signs of dizziness or vertigo in response to vestibular stimulation.
- Computerised dynamic posturography uses a special movable platform connected to a computer. It precisely evaluates balance function under various conditions.
- Vestibular Evoked Myogenic Potentials (VEMP) use loud sounds to test reflexes related to vestibular stimulation.
These tests allow doctors to pinpoint areas of dysfunction and determine appropriate treatments to help manage chronic balance problems originating from inner ear disorders.
Closing Thoughts
This post has provided an overview of the most common hearing tests used to evaluate hearing ability and screen for potential issues.
The audiogram remains the gold standard test, providing a detailed look at hearing sensitivity across different frequencies.
Tympanometry and otoacoustic emissions screening can also quickly identify potential problems with the middle ear or cochlea.
More advanced tests like ABR and vestibular/balance assessments may sometimes be warranted.
If you suspect you may have some degree of hearing loss, book a free home visit hearing test with us. The test lasts no more than 20 minutes, after which we will explain your results and provide recommendations for a hearing aid if this is deemed necessary.