How can i convert sound energy into electrical energy without using other energy sources?
Really can’t. The amount of energy in sound is extremely small. One problem is area. To capture all of the energy in a sound, you have to completely surround it with your converters, and even then, a few watts is all you can get. A speaker will work in reverse as a microphone to convert sound to electric power, but the output will be in the millivolts. At typically 8 ohms, even a volt will be only 1/8 of a watt. .
