A common call DigiKey gets is regarding claims of defective audio buzzers.
Many times when this happens, it ends up being a case where there is a misunderstanding regarding one of two buzzer categories.
In the Buzzer category for Driver Circuitry there are two options,
If you’re seeking a buzzer where you just apply a voltage and it automatically chirps you want to purchase an Indicator, Internally Driven.
People sometimes purchase Transducer, Externally Driven and it doesn’t end up working for them because this kind of buzzer requires an externally sourced square or sinusoidal wave signal of a specified frequency to operate. Applying a steady DC power source voltage to these types of transducers will not generate the desired results.