This document discusses converting sound energy into electricity using piezoelectric materials. It begins by introducing piezoelectricity and how certain materials can generate an electric charge when mechanically strained. It then proposes three methods for converting sound energy using piezoelectricity: 1) using a curtain and magnets to generate electricity from sound wave oscillations, 2) converting sound to heat then to electricity, and 3) using piezoelectric materials to directly convert the mechanical strain from sound waves into electric charges. The document concludes that sound contains large amounts of energy that can be harvested using these piezoelectric conversion methods.