EVERYTHING ABOUT ALL

Many computer users prefer listening to audio through headphones or a headset, rather
than using speakers. These devices are helpful when using portable computers, which do
not have very high-quality speakers, or when playing audio might disturb other people.


Headphones include a pair of speakers, which are attached to an adjustable strap that
can be custom-fitted to the wearer's head. Today, even inexpensive headphones have
reasonably high quality speakers, are lightweight, and are comfortable to wear. Nearly
any set of standard headphones can be plugged into the output jack of a computer's 
sound card, as long as they have a "mini" stereo plug. For headphones equipped with
larger plugs, adapters are available.

           
A headset includes one or two speakers and a microphone, all mounted to an adjustable
headstrap. The headset's microphone into the sound card's microphone input, and the
speakers connect to the sound card's speaker jack. Headsets replace both remote micro-
-phones and speakers and are useful for speech-recognition applications, or when uisng
the computer to make phone calls or participate in videoconferences.

Microphones are now important input devices, and speakers and their associated technologies
are key output systems. Today, nearly any new multimedia-capable PC includes a complete
sound system, with a microphone, speakers, a sound card, and a CD-ROM or DVD drive. Sound
systems are especially useful to people who use their computer to create or use multimedia
products, watch videos or listen to music, or participate in online activities such as
videoconferences or distance learning.


The speakers attached to these systems are similar to those you connect to a stereo. The
only difference is that they are usually smaller and may contain their own amplifiers. Other
wise, they do the same thing any speaker does: They transfer a constantly changing electric
current to a magnet, which pushes the speaker cone back and forth. The moving speaker cone
creates pressure vibrations in the air-in other words, sound.