The SISI-Test in Normal Listeners: An Investigation with Non-Commercial Equipment

Abstract

The SISI-test is an important development in modern audiology, especially because its basic design tends to eliminate a number of sources of error, and because it aims for a high degree of objectivity. The test signal as well as the procedure are clearly defined, and the possibility for the tester to bias results substantially reduced. Nonetheless, some disagreement as to normal values has arisen. It is felt that technical difficulties in keeping all parameters of the test signal in accordance with Jerger's precepts, could be partly responsible for this uncertainty. Examination of a commercial equipment illustrates some of the difficulties. Particular attention should be paid to the method of calibration. A non-commercial equipment is described, and test results from 40 normal hearing subjects are presented. The test was performed at 3 frequencies and at 3 SLs with 8 different increment magnitudes.