Ultrasonic devices use high-frequency sound waves, typically above the range of human hearing, to perform various functions. These devices can be found in many applications, such as cleaning, medical imaging, and pest control. For example, ultrasonic cleaners use sound waves to create tiny bubbles in a liquid, which help remove dirt and grime from delicate items. In the medical field, ultrasound machines utilize ultrasonic waves to create images of internal organs and monitor fetal development during pregnancy. Additionally, ultrasonic pest repellents emit sound waves that are unpleasant to pests, helping to keep them away from homes and gardens without using chemicals.