Input-output functions of cochlear microphonics in chronic experiments on awake rabbits.

Chronically implanted electrodes were used to record cochlear microphonics (CM) in awake rabbits. Test stimuli were sine waves of 1,250, 2,500, 5,000 and 10,000 Hz, with intensities increased from 40 to 100 dB SPL. By using this long-term method for registering the CM, we have found that the form of the input-output functions recorded is in agreement with that from acute experiments as described in the literature. Our method proved to be valid for recording CM with constant amplitudes over a period of 8-10 weeks. Our present results form a basis for further investigations concerning noise overload.