Test person operated 2-Alternative Forced Choice Audiometry compared to traditional audiometry

 

Background:

With a newly developed technique, hearing thresholds can be estimated with a system operated by the test persons themselves. This technique is based on the 2 Alternative Forced Choice paradigm known from the psychoacoustic research theory. Test persons can operate the system very easily themselves. Furthermore the system uses the theories behind the methods of maximum-likelihood fitting of the most probable psychometric function and a modification of the well known up-down methods in the estimation of the hearing thresholds. The combination of the 2AFC paradigm and the maximum-likelihood and up-down methods has proven effective and reliable even under suboptimal test settings. In non-optimal testing conditions i.e. as a part of a hearing conservation programme the headphone Sennheiser HDA-200 has been used as it contains hearing protection. This test-method has been validated as a comparison with traditional audiometry. A series of 30 persons (60 ears) have conducted traditional audiometry as well as self-operated 2AFC-audiometry. Test subjects are normal as well as moderately hearing impaired people. The different thresholds are compared.

 

Results:

2 AFC Audiometry is reliable and comparable to traditional audiometry. 2AFC audiometry tends to give thresholds 1-2 dB lower compared to traditional audiometry. In general standard deviations between the two test methods are below 4.5 dB for frequencies from (250-4000 Hz) and up to 6.7 dB for frequencies above 4000 Hz. Results from test-retest studies of 2AFC audiometry are comparable to test-retest results known from traditional audiometry under standard clinical settings.

 

Conclusions

2 Alternative Forced Choice audiometry can be a reliable alternative to traditional audiometry especially under certain circumstances, where it can be difficult to get skilled technical assistance to conduct the audiometry.