Desktop audio systems are external speakers to a computer that disable the poor fidelity provided by built-in speakers. These often have a low power internal amplifier. The standard audio connection is a stereo jack of 3.5 mm usually lime-green (according to PC 99 standards), for the PC sound.

Some computer monitors rather have built-in speakers. Laptops come with built-in speakers. Due to the limited space available in a laptop, the built-in speakers produce lower quality sound. For some users, connecting an existing stereo system to the computer is more practical, usually giving better results than some small computer speakers purchased at a reduced price. Desktop audio systems can also serve as an amplifier for an MP3 player.

What is a speaker?

A speaker is an output device with equipment that can be connected to devices that can play audio content, such as a personal computer, CD player or mobile phones. It can be active (they don't need an amplifier and can be connected to any device that has a headphone output) or passive.

What are headphones?

Audio headphones are peripheral output devices for receiving and listening to sounds and music. They are placed either over the ears or inside the external ears. They are equipped with small speakers and can be attached to a large number of electronic devices such as radios, cassette players, computers, mobile phones, etc.

The most frequently used audio headphones are binaural, being made for hearing with both ears, possibly with 2 channels of "stereo headphones". However, there are also special models called mono, made for 1 single sound channel, the same for both ears; in addition, there are also mono headphones for one ear.

Some models of audio headphones also have a small microphone attached to them, near the mouth.

What is a microphone?

A microphone is a peripheral output device that converts sound into electrical signals. It has many applications, being usually used in radio and television and telecommunications, but also in the music industry.

Several types of microphone are used, which use different methods to convert the air pressure variations of a sound wave into an electrical signal. The most common are the dynamic microphone, which uses a coil of wire suspended in a magnetic field; condenser microphone, which uses a vibrating diaphragm as a condenser plate; and the piezoelectric microphone, which uses a crystal of piezoelectric material. Microphones must usually be connected to a preamplifier before the signal can be recorded or played back.