I want to know what is standard input and output of piezo transducer and how it is calculated

bioramaniA microphone, any moving coil loud speaker and some piezo-electric transducers can be used to convert sound to electricity. #-Link-Snipped-#Thank you Sir

Hi I want to know which type of transducer are used to convert sound energy into electrical energy,Please post complete name ,your help will be appriciated. Thanks Sumit