A sound card, or audio card, is a computer expansion card that automates the input and output of audio signals to and from a computer. Sound cards are typically used to provide the audio output for multimedia programs such as music synthesis, video and audio editing, presentations, and video games. Most modern computers have sound capabilities built into the motherboard. However, some computer require addition expansion cards to provide audio output.
One of the most important parts of a sound card is the digital-to-analog converter, which converts recorded or generated digital data into analog format. The digital data is in the form of binary digits. The function of a sound card is to convert this digital data into analog data, which is the sound humans can hear. The output signal in the sound card is connected to either an amplifier, headphones, or external device using interconnections such as an RCA connector or TRS connector. If the connectors are too large for the space on the backplate, they will usually be off-board via a breakout box or auxiliary backplate.
More advanced sound cards usually include more than one sound chip to provide higher data rates and interaction between digital sound production and synthesized sounds. This allows for real-time generation of sound effects while using minimal data and CPU resources. Multi-channel digital-to-analog converters are used for digital sound production. These multi-channel converters are capable of simultaneously generating multiple digital samples of different pitches or volumes. They can also apply real-tie effects such as filtering or distortion.
Sound cards can also have a line in connector that picks up a signal from a cassette tape recorder. The sound card then digitizes these analog signals. Another common connector that may be found on a sound card is the microphone connector, which uses a microphone as an input device. The input from the microphone could then be used in applications such as speech recognition or Voice over IP.
There are two special types of sound output. These outputs are called 3-D sound and surround sound. Game developers usually use 3D sound to provide dynamic sound that changes based on a player’s position in a video game. In addition to using sound from different directions, 3-D sound allows for realistic recreations of sound maneuvering around obstacles. Surround sound is very similar, as it simulates sounds from several directions. The main difference is the fact that surround sound does not change based on the listener’s actions.
