Piezoelectric materials mimic the function of the cochlear sensory epithelium.
Cochlear hair cells convert sound vibration into electrical potential, and loss of these cells diminishes auditory function. In response to mechanical stimuli, piezoelectric materials generate electricity, suggesting that they could be used in place of hair cells to create an artificial cochlear epithelium. Here, we report that a piezoelectric membrane generated electrical potentials in response to sound stimuli that were able to induce auditory brainstem responses in deafened guinea pigs, indicating its capacity to mimic basilar membrane function. In addition, sound stimuli were transmitted through the external auditory canal to a piezoelectric membrane implanted in the cochlea, inducing it to vibrate. The application of sound to the middle ear ossicle induced voltage output from the implanted piezoelectric membrane. These findings establish the fundamental principles for the development of hearing devices using piezoelectric materials, although there are many problems to be overcome before practical application.
Department of Otolaryngology, Head and Neck Surgery, Graduate School of Medicine,  Kyoto University, Kyoto 606-8507,  Japan.
Takatoshi
T
Inaoka
Hirofumi
H
Shintaku
Takayuki
T
Nakagawa
Satoyuki
S
Kawano
Hideaki
H
Ogita
Tatsunori
T
Sakamoto
Shinji
S
Hamanishi
Hiroshi
H
Wada
Juichi
J
Ito
D000161:Acoustic Stimulation; D000818:Animals; D001489:Basilar Membrane / Q000187:drug effects / Q000502:physiology*; D003051:Cochlea / Q000187:drug effects / Q000502:physiology*; D004581:Electronics; D004976:Ethacrynic Acid / Q000494:pharmacology; D016057:Evoked Potentials, Auditory, Brain Stem; D005260:Female; D006168:Guinea Pigs; D007612:Kanamycin / Q000494:pharmacology
D007612:Kanamycin; D004976:Ethacrynic Acid