A Pure Tone Average (PTA) diagnosis doesn't exist as a stand-alone diagnosis. However, the Pure Tone Average (PTA) itself is a key measurement used in diagnosing hearing loss. A PTA is calculated from the results of an audiometry test and provides important information about an individual's hearing abilities.
Understanding Pure Tone Average (PTA)
The PTA is derived from hearing threshold levels at specific frequencies. These frequencies are typically 500, 1000, 2000, and 4000 Hz. The average of the hearing threshold levels at these frequencies is calculated for each ear separately. This value offers a general picture of a person's hearing level.
How is PTA Used in Diagnosis?
While the PTA itself isn't a diagnosis, it is an essential component in the diagnostic process. Here's how it's utilized:
- Identifying Hearing Loss: A PTA value above the normal hearing range (typically 25 dB HL or less) indicates the presence of hearing loss.
- Quantifying Hearing Loss: The severity of hearing loss is determined based on the PTA. For example:
- Mild hearing loss: PTA between 26-40 dB HL
- Moderate hearing loss: PTA between 41-55 dB HL
- Moderately severe hearing loss: PTA between 56-70 dB HL
- Severe hearing loss: PTA between 71-90 dB HL
- Profound hearing loss: PTA greater than 90 dB HL
- Monitoring Hearing Changes: Serial PTA measurements can track hearing changes over time, which helps in assessing the progression of hearing loss or the effectiveness of a treatment.
The Role of Audiometry in PTA
The audiometry test is performed to determine hearing thresholds at various frequencies, from which PTA is then calculated. During the audiometry test, the person being tested will indicate when they hear a sound. The minimum sound level in decibels (dB HL) that is audible at each frequency is recorded as the threshold. The PTA is then calculated by averaging the thresholds at the key frequencies.
PTA: An Essential Measurement Tool
In summary, PTA is a crucial tool in audiology. Though not a diagnosis itself, it is a pivotal measurement for the diagnosis, quantification, and monitoring of hearing loss. When combined with other audiometric tests, it assists clinicians to make a diagnosis.
