Effect of opening and draining the cochlea.

The WKB approximation was used in calculations of the pure-tone response of a two-dimensional inviscid model of the human cochlea and a three-dimensional inviscid model of the guinea pig cochlea. The common experimental procedure of opening the scala tympani was simulated. Basilar membrane displacement was unaffected at and beyond the peak, but was slightly lower pre-peak. The peak location shifted to a significant extent apically only when the fluid level in the scala tympani was lowered to less than 1/10 of normal depth.