What ordinary devices can be used as a piezoelectric transducer?

Question

Or since nobody would answer, what ordinary devices are used to make a piezoelectric transducer.

Answer 1

In terms of energy conversion, a small speaker or ear phone would do the same job.But it might not your expected answer.

Answer 2

Quartz! Piezoelectric transducers are based on crystals that are in a homeostatic place with respect to their charge. As soon as their is a force applied to the crystal, there is an electric potential between the atoms creating a voltage. The opposite is the same, a voltage will create a mechanical deformation.