Pure tone audiometry measures the capacity of a person’s auditory system (hearing). In this article, we will explain when and why you should book an appointment to see a specialist and request a hearing test.
The best diagnosis for your ears: pure tone hearing tests
As its name suggests, a pure tone hearing test uses pure tones to determine if a person can perceive every frequency in the audible spectrum.
This type of hearing test is classed as a subjective test and is carried out using a device called an audiometer.
The audiometer registers the results in an audiogram and reveals if your hearing is affected in terms of sound transmission in the middle ear (conductive hearing loss) or damage in the inner ear (sensorineural hearing loss), which helps the specialist to identify the most suitable treatment for the issue.
What types of pure tone hearing tests are used?
- Threshold hearing tests: these determine the subject’s capacity to recognize sounds at a specific frequency or volume. Headphones are used in this to establish the auditory or hearing threshold, which is marked by the last sound that the patient hears, and therefore represents their minimum hearing level.
- High-frequency (supraliminal) pure tone tests: these are used to evaluate the subject’s hearing fatigue and any disturbances or impairment above their threshold of hearing. The test is carried out under three main parameters: intensity, frequency and duration.
These hearing tests are usually carried out in a testing booth or acoustic chamber, which are covered with sound-absorbing materials the help to reduce the reflection of noise and standing waves.
How is hearing loss or impairment classified in a pure tone hearing test?
In pure tone audiometry, hearing thresholds are expressed in decibels of hearing loss (dB of HL) and are compared against the average hearing threshold (0 dB). Different degrees of hearing loss or impairment are classified in the following way:
- Normal hearing: threshold under 20 dB HL.
- Slight hearing loss: 20 – 40 dB HL.
- Moderate: 40 -70 dB HL.
- Severe: 70 -90 dB HL.
- Profound: 90 – 120 dB HL.
- Cophosis or anacusis (total deafness): in excess of 120 dB HL.
When should I have a pure tone hearing test?
It is vital you see your doctor as soon as possible if you detect any kind of hearing loss. We recommend you request a pure tone hearing test at several stages in your life:
- Possible deafness: hearing loss is a common issue, so if you notice any symptoms or have any issues with your hearing, get it tested as soon as possible to prevent further damage and find the correct treatment plan for you.
- Over-60s: a hearing test is recommended every 3 years for everyone over the age of 60 to detect possible age-related hearing loss (presbycusis).
- Certain high-risk diseases: your hearing can be damaged by certain diseases such as meningitis, depression and other serious illnesses, and should always be checked when you have recovered.
- Annual health assessment: while workers may opt out of this check-up that employers are obliged to offer in the workplace, it may be useful in detecting possible hearing issues.
Make a note of the different stages at which you should visit your medical specialist to request a pure tone hearing test – it could save your hearing.
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