The ST and SV are filled with the perilymph. ( C) Schematic drawing of a cochlear duct. Sound vibrations transmitted to the cochlea fluid in the scala vestibule (SV) through the OW travel up from the basal turn to the apical turn (red lines) and then back to the basal turn (blue lines) in the scala tympani (ST). ( B) Schematic drawing of a cochlear coil. AN, auditory nerve Co, cochlea EAC, external auditory canal In, incus Ma, malleus OW, oval window RW, round window St, stapes TM, tympanic membrane. ( A) Schematic drawing of the human auditory system. The oscillatory motion of the basilar membrane results in the shear motion of the stereociliary bundle of hair cells, resulting in depolarization of hair cells.įig. The organ of Corti contains the sensory cells of the auditory system they are known as hair cells, because tufts of stereocilia protrude from their apical surfaces ( Fig. The pressure wave propagated by the vibration of the stapes footplate causes oscillatory motion of the basilar membrane, where the organ of Corti is located. The scala media are membranous ducts that are separated from the scala vestibuli by Reissner's membrane and separated from the scala tympani by the basilar membrane. Sound vibration is transmitted from the ossicles to the cochlear fluids through the oval window as a pressure wave that travels from the base to the apex of the scala vestibuli through the scala tympani and finally to the round window ( Fig. The stapes, an ossicle in the middle ear, is directly coupled to the oval window. The scala vestibuli and scala tympani form a continuous duct that opens onto the middle ear through the oval and round windows. The cochlea consists of three compartments: scala vestibuli and scala tympani, which are filled with perilymph fluid, and scala media, which is filled with endolymph fluid ( Fig. The outer ear collects sound and funnels it through the external auditory canal to the tympanic membrane. The mammalian ear is composed of three parts: the outer, middle, and inner ears ( Fig. 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. The application of sound to the middle ear ossicle induced voltage output from the implanted piezoelectric membrane.
![piezo electric materials piezo electric materials](https://www.expo21xx.com/cipmedia/22345/52.jpg)
In addition, sound stimuli were transmitted through the external auditory canal to a piezoelectric membrane implanted in the cochlea, inducing it to vibrate.
![piezo electric materials piezo electric materials](https://i.ytimg.com/vi/yiZyBzFIlhk/maxresdefault.jpg)
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 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. Cochlear hair cells convert sound vibration into electrical potential, and loss of these cells diminishes auditory function.