Conversion of one form of energy into another is <em>transduction</em>.
In the auditory system, the ears receive<em> mechanical energy</em> in the form of vibrations and convert this energy into <em>electrical energy</em> to generate neural messages that reach the brain where this message is processed as sound.
Thus, one can say that the <em>mechanical energy of sound waves is transduced into electrical energy</em> in the ears to generate an auditory signal.