Why is Pure-Tone Audiometry a Common Hearing Test?
Pure tone audiometry is still the most widely used hearing test, despite being around for several decades. Not only does it detect the presence of hearing loss, but it also goes some way to establishing its type, severity and nature.
What is pure-tone audiometry?
Audiologists play patients a series of featureless sounds at various pitches during pure-tone audiometry, ranging from the deepest bass to the highest treble the human ear can perceive. Listening through a pair of high-quality headphones, the patient then indicates when they can detect noises piped to them. Audiologists then use this information to chart the nature of the hearing loss.
What's great about this method is that audiologists can plot the precise areas in which a patient has trouble hearing. Often, people with hearing loss have particular pitches that they can hear well, and those that they can't perceive at all. For instance, they may have no issues detecting bass sounds, but they might struggle with high-pitch noises.
When conducting a pure-tone test, the audiologist dials up the volume of sounds at different pitches, asking the patient to indicate when they first detect the noise. This procedure allows them to accurately map a hearing profile that they can then use to calibrate assistive hearing devices. The result is an audiogram – a kind of map which shows the topology of hearing loss at varying frequencies.
Why is pure-tone audiometry a popular test?
Audiologists widely consider pure-tone audiometry tests, the gold standard. But why?
In general, the quicker you can make a test, the better. Therefore, audiologists prefer pure-tone audiometry because they can complete the test in around 20 to 30 minutes. It means that the patient can be in and out of the office quickly and get the solutions they need faster.
Quantity of information generated
Most diagnoses provide yes and no answers. But pure-tone audiometry tests go much further than they. They give a characterization of the extent of the hearing loss and confirm whether the patient has it.
Audiologists test the patient's response to a range of tones, assessing the areas in which they have the most trouble and where they have the least. In some situations, there is a substantial loss of hearing across the entire range. In others, there are specific frequencies that the patient finds more difficult to detect than others.
Because audiologists can adjust the tone the patient hears granularly, they can perform highly accurate tests. The equipment allows them to change the volume of tones at tiny sub-decibel increments, letting them determine the actual severity of the patient's condition.
They're also able to adjust frequencies in slight increments, too, making it easier to calibrate hearing aid settings later on.
While the equipment required for pure-tone audiometry is highly precise, it is not expensive. Patients need a pair of headphones, a quiet environment and a computer/software to deliver sounds and record results.
Audiologists also want diagnostically useful tests. They want methods that allow them to assess the severity of the patient's condition to provide the optimal solution.
In many cases, patients do not need additional testing following a pure-tone test. Audiologists can simply prescribe interventions there and then, based on the results.
Other test options
While pure-tone audiometry is usually the first port of call, audiologists provide various other tests designed to supplement it.
For instance, speech testing is a specific type of hearing test that tries to determine whether patients have difficulty focusing on a single voice in the crowd.
Auditory brainstem response (ABR) tests monitor activity to determine whether nerve signals reach the patient's brain. Audiologists watch an output on a monitor, checking to see whether it responds to incoming noises.
In some cases, bone conduction tests can be helpful. The purpose of these is to find out which particular piece of machinery in the ear fails to do its job correctly. These are useful to find out whether something is blocking the middle ear as sound waves make their way from the eardrum to the cochlear.
Some patients also benefit from otoacoustic emissions, where audiologists directly stimulate the cochlear and measure its response.
If you're looking for pure-tone audiometry, then East Bay Audiologists, APC, can help. We offer a range of diagnostic and testing equipment to assess your hearing accurately and help you get the right treatment for your needs. Call us at 925-718-5592 to find out more.