Distortion product otoacoustic emissions: comparison of sequential versus simultaneous presentation of primary-tone pairs.

This Grason-Stadler GSI-60 system for measuring distortion product otoacoustic emissions (DPOAEs) allows the examiner to present one set of primary-tone pairs at a time (i.e., sequential presentation), or to present as many as four sets of primary-tone pairs at a time (i.

Immediate and short-term reliability of distortion-product otoacoustic emissions.

This study assessed the test-retest reliability of distortion-product otoacoustic emissions (DPOAEs) at four frequencies (550, 1000, 2000 and 4000 Hz) over three time intervals. The time intervals were: (1) immediate test-retest reliability, in which the retest followed the test without any delay or repositioning of the probe tip; (2) very short-term test-retest reliability, in which the retest followed a 10-20-min break and involved removal and re-insertion of the probe tip; and (3) short-term test-retest reliability, in which the retest was conducted 5-10 days after the test. Fifty normal-hearing women were tested with a commercially available system for measuring DPOAEs (Grason-Stadler, GSI-60), which generated primary tones at 65 dB SPL (L1=L2).