PTA stands for Pure-tone audiometry. This technique uses sound waves to assess the severity of hearing loss. The audiograms obtained using PTA from the same person can be very similar, unless there is a significant difference in step size. The British Society of Audiology (2011) states that a difference of up to 5dB HL is acceptable between audiograms, obtained from two different people. However, this does raise questions regarding test-retest reliability.
Pure-tone audiometry
Pure-tone audiometry is the primary hearing test used to diagnose hearing loss. It helps physicians identify a person’s hearing threshold level, the type and degree of hearing loss, and provides the basis for diagnosis and management. The hearing threshold test is, not only used for diagnosis but is, also used to monitor the progress of hearing loss.
Pure-tone audiometry is a non-invasive test that can take anywhere from 20 to 30 minutes to complete. It requires a quiet environment and headphones, and results are often very accurate. The process is noninvasive and offers a low-cost way to assess hearing function. In fact, most health care professionals rely on the results generated by this test.
When you suspect you might be suffering from hearing loss, the first step is to see an audiologist. An audiologist will be able to measure your hearing loss with pure-tone audiometry and provide advice on how to improve it. While pure-tone audiometry is the most common test, used to assess hearing loss, it is not the only test.
The accuracy of pure-tone audiometry depends on the instructions given to the participants and on the audiologist’s interpretation of their response behavior. Participants are, asked to sit quietly and respond when a tone comes on or is, turned off. Each ear must be tested independently, and the audiologist must ensure that each ear is receiving the same tone.
Pure-tone audiometry is a diagnostic method that identifies a hearing problem and is effective in determining the cause of the hearing loss. It consists of presenting pure-tone sounds to the patient’s better hearing ear. These sounds start at a low volume that is easy to hear and are, gradually increased in volume over time. The test is, performed using appropriate transducers, placed on the patient’s head to simulate a real-life audio environment. An audiologist sits outside of the sound booth to control the audiometer and observe the patient through an insulated window. The audiologist is also able to listen to the patient’s feedback through headphones.
Methods
The British Society of Audiology (BSA) publishes recommended procedures for PTA, as well as many other audiological procedures. These procedures are based on international standards and, therefore, increase the validity of the results. The BSA’s recommended PTA procedure is, described below.
PTA is a clinical audiometry test that measures a person’s hearing sensitivity to pure tones. There are three general methods for conducting this test: manual audiometry, automatic audiometry, and computerized audiometry. In the manual method, the examiner presents instructions to the patient before giving them earphones. Because earphones attenuate external noise, this test may not be appropriate for people with acoustic sensitivity issues. After giving the instructions, the patient is queried about their response.
Despite its clinical utility, pure-tone audiometry has its limitations. It is not able to identify all types of losses, including dead regions in the cochlea and neuropathies such as auditory processing disorder. It is also not possible to accurately predict a patient’s perceived degree of disability based on the PTA.
The most commonly used audiometric test is the pure-tone average. The results obtained with the pure-tone audiometry method are averaging of a person’s hearing thresholds at specified frequencies. This method allows comparisons to be more accurate. However, it cannot be used to measure the degree of deafness in one ear.
Another objective audiometry method is, brainstem evoked response audiometry. It uses small auditory evoked potentials (BAEPs) recorded using electrodes on the scalp surface. The BAEPs are, composed of seven waves that are, clinically analyzed based on their morphological characteristics.
Masking
In PTA Pura tone audiometry, the masking stimulus is, presented to the ear not under examination. The masking level is, increased in three-by-five-dB steps, until the noise reaches a threshold. A response occurs when the masking noise continues to be heard for three consecutive trials.
The MMax approach limits noise intensity based on bone-conduction threshold, which is 20 dB HL. It also guesses the lowest bone-conduction threshold, which decreases the likelihood of overmasking. However, if the threshold is too low, the masking may not completely mask the crossover.
Masking in PTA Pura tone audiometric tests is an important consideration. If the threshold is not at 0 dBHL, the test must use masking. This is, done by playing white noise in the non-test ear. This prevents the non-test ear from hearing the test tones, which allows clinicians to determine the true threshold.
There are two types of hearing thresholds: air conduction thresholds and bone conduction thresholds. Air conduction thresholds are generally 70 to 105 dB HL, while bone conduction thresholds are between 15 and 20 dB HL. If the air-bone gap is greater than 15 dB, the test is, considered sensorineural, whereas a lower air-bone gap is, not considered significant.
While PTA Pura tone audiometry has many clinical benefits, it does not accurately detect all loss types. For example, it can’t detect the dead areas of the cochlea, which can cause by neuropathies such as auditory processing disorder. In addition, it can’t predict the degree of disability that the patient will perceive.
Reliability
Reliability of PTA is determined by the test-retest reproducibility of the audiogram. Multiple audiograms obtained by PTA from the same person will generally be similar. As of 2011, the British Society of Audiology considers a 5dB HL difference on re-test to be acceptable. However, changes in step size may introduce uncertainties. Therefore, PTA should compare with other audiometric screening procedures.
PTA testing was, performed in, dedicated sound-proof rooms by experienced audiologists. Participants were tested using TDH-39 headphones to measure AC thresholds and a B-71 bone vibrator to measure BC thresholds. Each frequency was, measured with appropriate masking procedures. The researchers aim to establish the retest reliability of the PTA test in different age groups.
The PTA test is the gold standard for audiologic examinations. It provides information about the type and severity of a patient’s hearing loss. According to the American National Standards Institute, there are four types of PTA. Type 1 audiometry requires a fully equipped audiometer while Type 2 audiometry requires a loudspeaker. Type 4 audiometry includes basic audiometric functions.
While PTA pura tone audiometry is highly reliable, it cannot identify all types of losses. This method cannot identify the dead region of the cochlea or a neuropathologic condition such as auditory processing disorder. Furthermore, it is not reliable for predicting the degree of disability in patients.
Compared with the TFW, the AW test is more accurate than the TFW. Therefore, it may be a viable alternative for clinicians who are not well trained to perform tuning fork tests or who are unable to purchase tuning forks. However, it is important to note that the AW test should use to validate the results of PTA. This is because masking errors and questionable audiograms are common in clinical practice.
Smartphone-based audiometry
A recent study explored the effectiveness of a smartphone-based PTA pura tone audiometry test. Its results showed a high diagnostic value and potential for clinical applications. Despite this, accuracy was lower in children and elderly participants, suggesting technical limitations or impairments. In addition, older individuals may find the device difficult to use, which may be due to visual or functional decline.
The study also found a clear negative bias with uHear measurement results and narrow confidence intervals. This may have been due to the symmetry of the data collected from both audiometers and the smartphone. The strongest evidence of difference occurred at 1 and 4 kHz. The differences were statistically significant at the 5 % significance level.
Smartphone-based PTA pura tone audiometry has some limitations, but it generally follows the same procedure as conventional audiometry. The limitations of smartphone-based audiometry include crossover, which is when a sound presented in one ear can also be heard in the other. This can misconstrue hearing thresholds, especially in people with asymmetric hearing loss. To prevent crossover, a narrow-band noise near the test frequency is played in the non-test ear. This method is referred to as “masking” and is considered to be a useful tool for obtaining a true response from the test ear.
Smartphone-based PTA Pura tone audiometric tests can be used for a variety of clinical purposes. They are convenient and inexpensive for anyone who wants to screen their hearing for hearing loss. The accuracy of these tests is comparable to the results of, air-conduction-based audiometry but are, limited by the device used.
