الفهرس 
Chabter 1 : introductionOnly 14 pages are availabe for public view
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Abstract
Now a days of people around the world snuffer from hearing impairment especially in the industrial countries . therefore efforts indwelling prosthesis can be divided in to two major parts : one is can corned about the nearing – aid systems developed for the people who have partial hearing loss , and the other one concerns cochlear been invented to improve speech perception of hearing impaired people , but it have a poor quality and provide limited gain . so , in this the sis we try to introduce some solutions for these limitations by using both MEMS and comes technologies .
MEMS has been in identified as one of the most promising tech neologies for the 27st century and has the potential to revolutionize both industrial and consumer products by combining silicon – based micro lector system with micro aching technology . Its techniques and micro system – based devoices have the potential to dramatically affect all of our lives and the way we live .
This thesis presents a piezoelectric cantilever microphone in order to avoid the residual stress existed in the canister in the clamped – clamped ore , and it is easier to fabricate compared to capacitive microphone since the deflection can be measured directly . compared to condenser micro phones the noise however perform ance is worse .
In recent year low voltage low power analogy VLSI circuits have received considerable attention in the field of microelectronics , which are useful in high frequency applications and low voltage low power application . the current conveyor is a versatile analog device , which is intended to be used with other circuit components to implement many analog signal processing function . In this these is a preamplifier circuit based on current convey or technique for hearing aid devices is designed and simulation results and layout for the circuitous done , where the main purpose is to have as low power consumption as possible . this is due to the fact that as the technology us scaling down the number of transitory on chip goes larger and thus the average power consume piton is getting lager . this means that analog circuits should be able to work under power constraint so as to minimize the overall power consume piton and thus enlarge the used battery life .