ASA 129th Meeting - Washington, DC - 1995 May 30 .. Jun 06

5pPP16. Polynomial correlation used to estimate the degree of nonlinearity of the frog inner ear system.

Pim van Dijk

Inst. of Audiol. KNO), Univ. Hospital Groningen, P.O. Box 30.001, 9700 RB Groningen, The Netherlands

The nerve fiber response to Gaussian noise was measured in the American bullfrog (Rana Catesbeiana). By cross correlating the stimulus and the response, Wiener kernels of the frog inner ear system were obtained. The first- and second-order Wiener kernels were fully calculated, while for the 3rd- to 10th-order kernels only the diagonals (also known as polynomial correlation functions) were computed. The data for fibers above 500 Hz could be described by a BPNL sandwich model. A new least-squares method was used to determine both filter functions in the model from the Wiener kernels. Preliminary analysis showed that response components could be found in kernels up to the order of 5. This suggests that the degree of the nonlinearity of the frog inner ear is at most 5.