Methods, apparatuses, and systems for detecting internal defects of a protective headgear are provided. An example apparatus may include a protective headgear, an actuator element integrated within the protective headgear, a sensor element integrated within the protective headgear, and a processor element electronically coupled to the actuator element and the sensor element. In some examples, the processor element is configured to cause the actuator element to generate a first ultrasonic wave, wherein the first ultrasonic wave is propagated in the protective headgear, and receive a first output from the sensor element in response to the first ultrasonic wave.