A Langevin transducer is a device that converts electrical energy into mechanical energy and vice versa, primarily using the piezoelectric effect. It consists of a piezoelectric material sandwiched between two metal electrodes, which vibrate when an electric current is applied. This vibration can generate ultrasonic waves, making it useful in various applications like ultrasonic cleaning and medical imaging. In addition to its use in generating sound waves, the Langevin transducer can also detect sound waves and convert them back into electrical signals. This dual functionality makes it valuable in fields such as ultrasonics, sonar, and non-destructive testing, where precise measurements and imaging are essential.