Glenis R. Long
Dept. of Audiol. and Speech Sci., Purdue Univ., West Lafayette, IN 47907
Carrick L. Talmadge
Purdue Univ., West Lafayette, IN 47907
DPOAEs generated by the interaction of one external tone and one spontaneous otoacoustic emission (SOAE) are maximal when the external stimulus begins to suppress the level of the emission. Consequently, investigations of the f2/f1 and L2/L1 ratios producing maximum distortion are limited. DPOAEs generated in this way were systematically compared to DPOAEs generated by two external tones. First, another external tone with the same frequency as the SOAE was inserted into the ear canal to entrain the spontaneous emission and maintain a known signal at the frequency of the spontaneous emission. Second, DPOAEs generated by two external tones with same frequency and level ranges as above were measured in ears with no spontaneous emissions in the frequency range examined. The pattern of maximum DPOAEs are interpreted in terms of the excitation patterns of external tones and SOAEs on the basilar membrane.