Acoustic energy is an important form of energy which is generated and unused all around us. Despite the prevalence of acoustic energy a major challenge of energy harvesting is the low power density in typical acoustic noise fields. With a larger focus on green energy, acoustic energy is one of the vastly available energy sources and so harvesting this energy plays an important role in research. Unconventionally a thermoacoustic engine converts thermal energy to acoustic energy via its core, comprising a porous material that is sandwiched between two heat exchangers. The induced acoustic wave can be converted into electricity by introducing novel environment friendly energy converters. Integration of the thermoacoustic technology with piezoelectricity tends to be promising, since the piezoelectric ceramics are sensitive and operating efficiently at high frequencies. Thermoacoustic technology is receiving growing interest in research for its many advantages, such as having no moving parts, being environment friendly and the possibility of using other renewable energy for its operation. This paper aims at providing a review on various acoustic and thermoacoustic energy harvesting techniques and the maximum power generated from each of these techniques.