Vestibular and cochlear responses to acoustic transients. Some properties of whole-nerve action potentials in pigeons.

In a previous paper attention was drawn to the possibility of introducing the labyrinth as an organ for sound perception. Behavioural responses of the guinea pig as well as electrophysiological results in the pigeon indicated that fenestration of the labyrinth might be an alternative to cochlear implants. In this paper gross electrode electrophysiological responses to transient acoustic stimuli in the pigeon are further analysed and the influence of fenestration of the lateral canal and cochlea extirpation upon these responses was studied. The vestibular AP generated by sound stimuli could, among other things, be distinguished from the cochlear AP by its shorter latency. The dynamic range of this vestibular AP is at least 30 dB. The largest vestibular responses were obtained for stimulus frequencies below about 1.5 kHz. A simple hydromechanical model to explain the observed responses is discussed.

Evidence for sound perception with the labyrinth.

A report is presented of experiments on guinea pigs and pigeons concerning behavioural and electrophysiological responses of the labyrinth to sound. In the guinea pigs the cochlea was destroyed on both sides by CO2 laser radiation and fenestration of the lateral semicircular canal was done. In the pigeons the cochlea was removed before fenestration. On account of the results obtained, fenestration of the lateral canal in patients with bilateral total cochlear loss can be considered as an alternative to monopolar cochlear implants.