The influence of cochlear temperature on the electrical travelling wave pattern in the guinea pig cochlea

Cochlear microphonics (CM) were recorded in the guinea pig using differential recording from the first and third cochlear turns as well as by using a 10-electrode array inserted in the scala tympani of the basal turn. The excitation profile as represented by the CM was quantified by amplitude and phase data, and was measured at normal temperature (38 degrees C) and a 10 degrees lower cochlear temperature. It appears that the CM pattern shifts toward the base of the cochlea as a result of cooling. This is explained on the basis of an increased compliance of the basilar membrane with an optional influence of increased viscosity of the perilymph.