iezoelectric-based energy harvesting is an efficient way to convert ambient vibration energy into usable electric energy. The piezoelectric harvester can work as a sustainable and green power source for different electric devices such as sensors and implanted medical devices. However, harvesting energy from sound need more research and investment. This dissertation aimed to study and analyze the piezoelectric-based energy harvesting from sound, especially in pipes and acoustic resonator. To reach that aim, a more accurate model for piezoelectric composite beams was built first, which can be adopted for the modeling of different kinds of energy harvesters. The apparatus consists of a cantilevered beam harvester with a piezoelectric layer. Matlab and Ansys15 are used for analysis . Harvesting system includes an acoustic resonator and cantilever beamthat are locating inside the acoustic resonator. A coupled electromechanical modal model based on Euler-Bernoulli theory was used. The model includes both direct and inverse piezoelectric effects and can provide a better prediction for the dynamic response and energy output of a harvester. The quarter-wavelength acoustic resonator is used in its first eigen-frequency. The amplified acoustic pressure inside the tube drives the vibration motions of piezoelectric plates, resulting in the generation of electricity due to the direct piezoelectric effect. In order to increase the amount of the harvested energy, the acoustic resonator length has been designed to have the same eigen-frequency as each piezoelectric plates. To increase the total voltage and power, multiple PZT plates were placed inside the tube. The number of PZT plates to maximize the voltage and power is limited due to the interruption of air particle motion by the plates. It has been found to be more beneficial to place the piezoelectric plates in the first half of the tube rather than along the entire tube. An incident sound pressure level is 100 dB. Three different arrangement of piezoelectric plates are used: the aligned and zigzag configurations. With the zigzag configuration which has the more open path for acoustic air particle motions, the significant increases in the harvested voltage and power have been observed. Keywords : Smart material, Energy harvesting, Sound, Acoustic, PZT plates, Cantilever beams, Acoustic resonator