A microphone is a device that changes acoustic energy into an electric current—one that can be altered and manipulated. In this lesson, we will look at various types of microphones, explain how they work, and help familiarize you with popular mics you will see in the studio and on stage. Any device that converts one form of energy into another form of energy is called a transducer. Microphones are used in many different applications and are typically the first stop in the signal flow of our recording path. Prior to the advent of being able to record sound was the ever-existent need for communication. Hence, the invention of the telephone served as the genesis of an array of inventions and concepts still used in audio today, the microphone being one of the most prominent among them. The invention of the telephone has been credited to Alexander Graham Bell although there is now controversy surrounding that claim. Nevertheless, we know that in 1876 the first successful transmission of the human voice via a “liquid transmitter” (a microphone inside the telephone) thrust many into the pursuit of improving the quality of the sound transmitted. The race was on!