Audio Hardware - Notes 4

Sound boards (or cards) enhance the computers ability to produce audible sounds from digital information processed by the CPU. Digital information stored in sound files are processed in the computer and sent to external speakers or headphones. The two most used sound files have an extension of .wav or .au. The .wav files (often called wave files) can be created with sound recorder software supplied in Windows 3.1, 95, NT, or stand alone programs. Audio information from an external sound device such as a microphone, VCR, tape player, radio, or TV can be connected to the sound card input allowing the capture of audio on the computer hard drive.

Sound boards also provide additional communications capabilities on the internet. Two way audio communication called internet phone lets two persons speak to each other using a modem connected to their internet service provider. Some web sites provide "streaming audio" to give a continuous stream of audio similar to broadcast radio. A special program on your computer such as Real Audio will play the streaming audio through your speakers or headphones. Streaming audio captures and buffers audio information in computer memory, then starts processing and playing audio during the time that additional audio data is being received. This technique produces a continuous stream of audio without saving information into an entire audio file and then playing it back. The internet is a great source for audio files that you can download and playback.

Sound cards can also be used with "voice" word processors which enable the user to speak into a microphone and have the words displayed on the monitor.  Once the words are captured in the word processor, they can be formatted and printed by the user.