The working principle of MICROPHONEMicrophones work based on the principle of converting sound waves into electrical signals. The working principle of a typical microphone involves the following steps:
Sound Wave Capture: When sound waves from the surrounding environment reach the microphone, they cause the diaphragm or membrane of the microphone to vibrate. The diaphragm is a thin, flexible material that is sensitive to sound pressure variations.
Conversion of Sound Waves into Mechanical Motion: As the diaphragm vibrates in response to sound waves, it moves back and forth. The movement of the diaphragm is proportional to the variations in air pressure caused by the sound waves. This mechanical motion carries the acoustic energy of the sound waves.
Transduction: The mechanical motion of the diaphragm is converted into an electrical signal through various transduction methods used in different types of microphones.
In Dynamic Microphones: Dynamic microphones utilize electromagnetic induction. The diaphragm is attached to a coil of wire suspended within a magnetic field. As the diaphragm moves in the magnetic field, it causes the coil to generate an electrical current. This current is proportional to the velocity of the diaphragm's movement and represents the audio signal.
In Condenser Microphones: Condenser microphones use the principle of capacitance. The diaphragm acts as one plate of a capacitor, and a backplate acts as the other plate. When the diaphragm moves due to sound waves, the distance between the diaphragm and the backplate changes, resulting in a variation in capacitance. An electrical charge is applied to the capacitor, and the variations in capacitance generate a corresponding voltage signal.
In Ribbon Microphones: Ribbon microphones employ a thin metal ribbon as the diaphragm. The ribbon is suspended in a magnetic field, and as it vibrates in response to sound waves, it generates a small electrical current. This current is induced in the ribbon due to its movement within the magnetic field.
Amplification and Signal Processing: The electrical signal produced by the microphone is typically very weak and needs to be amplified and processed further. The signal is sent to an amplifier or preamplifier stage to increase its level and make it suitable for recording or transmission.
Output: The amplified electrical signal is then sent to an audio interface, mixing console, recording device, or other audio equipment for further processing, recording, or playback.
It's important to note that there are various types of microphones, and each type may have its unique working principle and construction. The principles described here represent the basic working principles of commonly used microphones. The specific design and implementation may vary depending on the microphone type and technology used.