Speaker
Speaker is one of the major part in this device. It is place inside the ear cup. The "anti-sound" created by the noise-canceling circuitry is fed into the headphones' speakers along with the normal audio; the anti-sound erases the noise by destructive interference, but does not affect the desired sound waves in the normal audio. The minor part in the speaker are diaphragm, suspension, basket, spider, magnet, dust cap, and voice coil, just like what we can see in the picture above. A system's speaker is the component that takes the electronic signal stored on things like CDs, tape and DVDs and turns it back into actual sound that we can hear. A speaker is essentially the final translation machine -- the reverse of the microphone. It takes the electrical signal and translates it back into physical vibrations to create sound waves. When everything is working as it should, the speaker produces nearly the same vibrations that the microphone originally recorded.
Microphone

Microphones just convert a real sound wave into an electrical audio signal. In order to do so, they have a small, light material in them called the
diaphragm. When the sound vibrations through the air reach the diaphragm, they cause the diaphragm to vibrate. This in turns will somehow cause an electrical current in the microphone to vary, whereupon it is sent out to a mixer, preamplifier or amplifier for use. Microphones are typically classified according to how the diaphragms produce sound. A microphone placed inside the ear cup "listens" to external sounds that cannot be blocked passively.
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