The Pure Tone Audiometry (PTA) test is a painless hearing test where you listen to tones through earphones and indicate when you hear them. Here's a breakdown of the procedure:
Purpose of the PTA Test
The PTA test determines the quietest tones you can hear at different frequencies, helping to identify the type and degree of hearing loss.
Preparation
- There's typically no special preparation needed.
- You may be asked about your hearing history.
The Test Procedure
- Setup: You will be seated in a soundproof booth or a quiet room.
- Headphones: You will wear headphones or insert earphones.
- Instructions: The audiologist will explain that you'll hear a series of beeps or tones and you need to respond every time you hear a sound, even if it's very faint. You typically respond by raising your hand, pressing a button, or verbally responding "yes."
- Tone Presentation: Pure tones (single-frequency sounds) are presented to one ear at a time. The audiologist controls the frequency (pitch) and intensity (loudness) of the tones using an audiometer.
- Threshold Determination: The audiologist starts with a tone that is easily heard. The intensity is then gradually decreased until you can no longer hear it. The intensity is then increased again until you respond. This process is repeated to determine the softest sound you can hear at each frequency. This is called your threshold.
- Frequency Range: The test typically covers a range of frequencies from 250 Hz to 8000 Hz, which are important for understanding speech.
- Bone Conduction Testing (Optional): In some cases, bone conduction testing may also be performed. A bone vibrator is placed behind the ear, on the mastoid bone. This vibrates the skull and stimulates the inner ear directly, bypassing the outer and middle ear. This helps to determine the type of hearing loss (e.g., conductive, sensorineural, or mixed).
- Results: The results are plotted on an audiogram, a graph that shows your hearing thresholds at each frequency.
Interpretation of Results
The audiogram helps the audiologist determine:
- Degree of Hearing Loss: Mild, moderate, severe, or profound.
- Type of Hearing Loss: Conductive (problem in the outer or middle ear), sensorineural (problem in the inner ear or auditory nerve), or mixed.
- Configuration of Hearing Loss: Which frequencies are most affected.
Duration
The PTA test usually takes about 20-30 minutes.
In summary, the PTA test involves listening to a series of tones at different frequencies and intensities through earphones, and indicating when you hear them. The results are recorded on an audiogram, which helps determine the type and degree of any hearing loss.
