Question

Example of transformation of heat energy to sound energy

Answer 1

They key is to transform energy in the form of heat into vibrations, or oscillations, of some membranes, or crystals.

Gradients of temperature force movement/stress of materials, by means of pressure - heat expands volume. Gradient means - it does it unevenly. If it’s coordinated properly, you can get oscillations, that in turn can also be transformed - to sound in air or electricity.