INTRODUCTIONUltrasound represents sound waves with frequencies above 16 kHz, higher than those that can be heard by humans. The upper limit of ultrasonic frequency is generally considered to be 5 MHz for gases and 500 MHz for liquids and solids [1], while the lower limit of frequency is considered to be 20 kHz [2]. Ultrasonic waves can be divided into two main areas [1, 3], low amplitude, i.e. propagation linked to the effect of the medium on the wave, and high amplitude, in which propagation is due to the effect of the wave on the medium. For many materials, low-amplitude propagation has proven to be a powerful analytical technique for studying physicochemical properties [4]. Low-power ultrasonic irradiation produces no chemical changes, while high-power ultrasound causes permanent physical/chemical changes in the material [3, 5, 6]. High energy input produces cavitation and micro-flows in liquids, heating effects and surface instability at liquid-liquid and liquid-gas interfaces [3, 7, 8]. Ultrasound has provided a method for exploring some of the primary properties of materials. Sonication offers a much better way to induce these physical and chemical changes with higher efficiency and shorter treatment times. Understanding the mechanisms of the different effects of sound is important in connection with its applications in different fields (medicine, food, chemistry). There is a considerable need to improve the understanding of the mechanisms in order to assess the performance and limitations involved in its various applications. This study explains the mechanisms of ultrasonic irradiation with particular attention to the field of nanomaterial synthesis. .... middle of paper ...... such as hydroxyl radicals and hydrogen peroxide, which induce drastic reactive conditions in liquid media [11]. Sonochemistry has various beneficial effects on chemical reactions and processes from the perspective of analytical chemistry. Some of them are: • Decreased reaction time and/or increased yield • Use of lesser forcing conditions, e.g. lower reaction temperature • Possible change of reaction pathway • Use of less or avoidance of phase transfer catalysts • Degassing forces reactions with gaseous products • Use of crude or technical reagents • Activation of metals and solids • Reduction of any induction period • Improvement of reactivity of reactants or catalysts • Generation of useful reactive speciesIn this way, ultrasound remains unique, since no other sample processing method can produce such effects [13, 14].