Study Of Key Technologies Of Piezoelectric Bone-condiicutir Hearing Device Of Intermediate Fixed Support-type

Based on the inverse piezoelectric effect of the piezoelectric oscillator andbone-conduction theory, using the piezoelectric oscillator as the vocal element, this paperpresents a piezoelectric bone-conduction hearing device that is suitable for external wear andmakes relevant study about its key technologies. The specific content is as follows:1.Development background and research condition of the bone-onduction hearingdevice in-and abroadWhen the bone-conduction hearing device works, the vibrator transmits the wavesignal to inner ear by means of vibrating the skull. The bone-conduction hearing device isnot only suitable for patients who have auditory impairment because of external auditorycanal stricture,suppurative otitis media,etc;But it is also suitable for normal people in themanner of liberating their ears，protecting their ears from hearing loss and especially suitablefor people who work in the environment with great noise.The development condition of thebone conduction hearing device in-and abroad indicts: electromagnetic bone-conductionearphones and cellular phones are the mainstream of the current market. Piezoelectricbone-conduction hearing device has become the focus of the current research because of itsadvantages such as low power consuming,no electromagnetic radiation,a compactstructure,light weight,etc,the implantable type has already become very prevalent,howeverthe type that id suitable for external wear just has its infancy.2.Releated theory of the piezoelectric bone-conduction hearing deviceIntroduce some basic knowledge of hearing such as physical nature of sound, theconstruction of the human ear, the ways that human perceive sound, and hearing threshold,etc. Introduce some basic piezoelectric knowledge such as the performance parameters of thepiezoelectric ceramics, the equivalent circuit of the piezoelectric oscillator, the resonantcharacteristic of the piezoelectric oscillator, the hysteresis characteristic of the piezoelectricoscillator, the amplitude-frequence characteristic of the piezoelectric oscillator.These basichearing and piezoelectric knowledge provide the basis for the study of the bone-conductionhearing device.3.Finite element simulation analysis of intermediate fixed support-typepiezoelectric oscillator of different shapesUse Ansys to do static analysis, modal analysis, harmonic response analysis ofintermediate fixed support-type piezoelectric oscillator of different shapes,analyze andcompare the largest deformation displacement, the modes and the harmonic response curveof intermediate fixed (point and line) support-type piezoelectric oscillator of differentshapes,determine the intermediate line fixed support-type rectangular and square piezoelectric oscillators as the test objects of the further study.4.Experimental test of the critical performance of the line fixed support-typerectangular and square piezoelectric oscillatorConduct a test of the radial voltage-displacement deformation characteristic and theamplitude-frequency characteristic of the intermediate line fixed support-type rectangularand square piezoelectric oscillators, compare the experimental results with the simulationresults to prove the correctness of the simulation results. Conduct a test of the waveformresponse characteristic and hysteresis characteristic of the two different piezoelectricoscillators, compare and analyze the experimental results to prove the the feasibility of thetwo different piezoelectric oscillators to be used as the vocal elements of thebone-conduction hearing device.Conduct a test of the influence of the variations of thesupport column’s dimension parameters of the piezoelectric oscillator on the displacementand loudness of the piezoelectric oscillator.5. Structure design and performance test of the hearing deviceDescribe the theory of the frequency demultiplication of the Electro-acoustics.Through the method of simulation, determine the dimension parameters of thehigh-frequency and low-frequency piezoelectric oscillators and their support columns,whichare the components of the hearing device，also the frequency division point is determined.Design the whole structure of the hearing device, the roof, base,etc and manufacture theprototype. Conduct a test of the voltage-displacement characteristic, the voltage-soundnesscharacteristic, the step response characteristic, etc of the hearing device,make a study of thedynamic response performance of the prototype. Stimulate the prototype with sinevoltage-signals of different frequencies and test the soundness，analyze and compare theexperimental results, the characteristic of the low-frequency piezoelectric oscillator is a littlebetter than the high-frequency piezoelectric oscillator in the medium and low frequencyarea,the characteristic of the high-frequency piezoelectric oscillator is much better than thelow-frequency piezoelectric oscillator in the high frequency area.