Noise pollution caused by engines is one of the most significant environmental challenges facing modern societies, particularly in areas near airports, factories, and congested roads. High and continuous noise levels not only affect public comfort but may also lead to sleep disturbances, stress, and reduced concentration, making noise reduction an important environmental and engineering priority. The main sources of engine noise include internal combustion processes, the movement of mechanical components, exhaust gas flow, and vibrations generated during operation. Noise intensity varies depending on the type of engine, rotational speed, engineering design, and operating conditions. Environmental and mechanical engineering have contributed to developing several solutions to address this problem. These include advanced silencers, sound-insulating materials, and exhaust systems designed to reduce the intensity of sound waves. Engineers are also developing more efficient and quieter engines by improving combustion processes, reducing mechanical vibrations, and using electronic control technologies. Modern solutions also include the use of computer simulations to study sound wave propagation and analyze noise sources before engines are manufactured. This helps engineers improve designs and select suitable materials. Furthermore, the use of electric motors in certain industrial applications and transportation systems helps reduce noise associated with combustion and conventional mechanical operations. Addressing noise pollution requires integration between engineering innovation, environmental planning, and regulations that establish acceptable noise levels. Designing quieter engines is not merely a technical improvement; it is an important step towards protecting human health and creating a more sustainable and comfortable environment for future generations. Assist. Lecturer Al-Buraq Haider Mohsen