Can the piezo element sound alone? many customer ask this kind of questions,but we answer as below:the piezo film is made into a very thin original film, and the sound cannot be produced without a resonant cavity. Even the sound is small and can only be heard in a very quiet environment. And only when the piezoelectric honeycomb has a resonant cavity, it can make a loud sound after power-on, even in a noisy environment. For example, the piezo sounder and the shell can be turned into a buzzer or an alarm, which can emit different sounds as required by customers. Therefore, it is not meaningful to say the volume of the sound emitted by the buzzer alone, and the volume must be determined with the cavity. But generally speaking, the bigger the internal type piezo element and the bigger the shell, the louder the sound! This information comes from FBelec's engineering department