AUTOMATED METHOD FOR TESTING AUDITORY SENSITIVITY
U.S. Patent Nos. # 6,496,585, and 7,704,216
What is AMTAS?
AMTAS is an automated method for obtaining a diagnostic audiogram including air and bone conduction thresholds with masking applied to the non-test ear. It is based on a psychophysical procedure that uses the patient’s responses to determine signal levels needed to find auditory thresholds. The test is self-paced so that patients proceed at the rate that is comfortable for them. Feedback is provided to the patient that helps them distinguish between test tones and other auditory sensations. Quality indicators provide information about the validity of results. The test can be monitored in real time from any computer with internet access or from a wireless device on a local area network.
Who are appropriate patients for AMTAS?
Anyone who can follow the instructions used for manual audiometry can be tested by AMTAS . Separate adult and child versions insure that the test presentation is age appropriate. The child version has a training module that teaches the patient to respond to test tones and ignore masking noise. A variety of visual reinforcements are selected by the patient to adapt the test to the interests of the child.
How is AMTAS different from other automatic hearing tests?
Most automated hearing tests are used for industrial testing and do not test bone conduction or use contralateral masking. Although AMTAS has an air-conduction only option, it is designed to obtain a complete diagnostic audiogram.
AMTAS employs quality indicators that provide information about the likelihood that the test results are valid. The quality indicators are based on quantitative measures of patient behavior which are compared to results obtained in a clinical trial. The quality indicator function is a patented feature.
What hardware is required to administer AMTAS?
AMTAS is administered by computer control of commercial audiometers. Because virtually all modern diagnostic audiometers are externally controllable, AMTAS can be implemented on a wide variety of hardware platforms. The typical system includes a personal computer, audiometer, and touch screen monitor.
What transducers are used to present the stimuli?
In order to fully automate the diagnostic audiogram, one transducer arrangement is needed that can be left in place for the entire test. Currently-used audiometric earphones do not meet this requirement because they produce an occlusion effect, an artificial increase in sensitivity to bone-conducted stimuli caused by covering the ear (or placing an insert earphone). Consequently in manual audiometry, bone conduction is tested with the vibrator on the mastoid of the unoccluded test ear with an earphone on (or in) the non-test ear for masking. The arrangement has to be reversed to test the other ear. As a result, typically three different transducer arrangements are necessary to acquire a complete audiogram.
The solution is to use forehead placement for the bone vibrator and non-occluding earphones covering both ears which can be used for presenting air conduction test signals and masking noise. An experimental non-occluding earphone has been developed that meets the requirements for a single transducer arrangement and has the added benefits of ambient sound exclusion (reducing the need for sound treated rooms) and increased interaural attenuation (reducing masking problems).
What are the advantages of automated testing?
1. Efficiency. Audiologists are under increasing pressure to increase efficiency and use their time in a cost-effective manner. In the U.S. , the profession is transitioning to a doctoral model. This transition is the result of the explosive growth in the scope of practice which has rendered masters degree training programs incapable of providing adequate training in all the areas in which audiologists must be competent. The doctoral transition will result in higher educational costs and higher salaries. The health care system cannot afford to pay doctoral level professionals to perform tasks that can be automated. Audiologists time should be spent performing the tasks that require doctoral training, such as testing difficult-to-test patients, counseling, aural rehabilitation, and case management. AMTAS provides the capability to test multiple patients simultaneously without examiner intervention and monitor the tests in real time from remote locations.
2. Access . The capability to perform accurate diagnostic testing without expensive personnel will increase access to hearing testing. An automated test procedure can be located in primary care settings, schools, and other locations where audiologists are not available. The results can be used to determine whether referral to other professionals is appropriate.
3. Accuracy. Audiometry is well-suited for automation because it is governed by a set of rules that are easily expressed as algorithms. Once implemented in software, the automated system doesn’t forget as even the most experienced clinicians sometimes do. When there is a likelihood that the result is inaccurate, the quality indicators used by AMTAS alerts the examiner so that manual testing can be performed when a skilled clinician is needed to obtain an accurate test.
Who developed AMTAS?