Wthat about an oscillator based on an acoustic feedback

[ivand58]

When I saw the entries in your blog about the ceramic capacitors, I realized that a demo with oscillator based on an acoustic feedback of the ceramic caps would be very helpful for understanding the impact of that sort of vibrations in the circuits ...   

[Zero999]

I've never tried it but I imagine it would rely on close coupling between the PCB and the speaker and lots of gain.

Maybe an SMT capacitor would be required as it will have better mechanical coupling to the PCB?