I already had a hunch as to what was going on in the module. I decided to trace its schematic and it ... connections to the monostable circuit shown below to make another/your version of the piezo ...

It uses a cheap and cheerful vibration sensor to drive a piezo-sounder. As can be seen in the circuit diagram, it is wired around one tiny ... The vibration sensor module is monitored by GP5 (pin 2) ...

The DT9837A USB module for sound and vibration analysis provides four independent, 24-bit integrated electronics piezo electric sensor inputs that synchronize with a tachometer input to deliver ...