Browse Definitions :

sound card

What is a sound card?

A sound card is a computer component responsible for generating and recording audio. It enables users to connect analog speakers, headphones and microphones to their computer. Most modern computers have a built-in sound card in the motherboard.

Generating audio on computers is challenging because sound is fundamentally analog, while computers are digital devices. Moreover, the human ear is incredibly sensitive to even the slightest changes in sound. The sound card's primary function is to convert digital signals into analog output for speakers and headphones. It also converts signals from microphones to digital input.

typical motherboard configuration

How do sound cards work?

A sound card operates through a digital-analog-converter (DAC) and an analog-digital-converter (ADC) and uses dedicated chips to lessen the CPU load. A preamplifier (preamp) boosts signal levels and controls volume. It may also be able to perform audio processing, such as audio equalization.

Sound cards used to be expansion cards for early computers, often with ISA or PCI slots. Newer cards use PCIe. However, as audio recording and playback became ubiquitous, and the cost of components decreased, it became common to incorporate basic sound card functionality into the motherboard. Although most computers no longer have physical sound cards, the term "sound card" still refers to the chips and functionality that provide audio output.

how an analog-to-digital converter works
Sound card employs analog-digital-converter (ADC), which changes continuous analog signals to discrete digital ones.

At the very least, a sound card provides a 3.5 mm stereo audio out and audio in TRS (tip, ring, sleeve) jack. However, many modern devices now use a single 3.5 mm TRRS (tip, ring, ring, sleeve) jack that combines both the headphone and microphone into a single port. Advanced sound cards offer additional input and output jacks. These may have additional 3.5 mm jacks for 5.1 or 7.1 channel surround sound, digital outputs or a digital optical audio port. Older sound cards may also have a MIDI or joystick port.

External sound cards are typically called audio interfaces, and they usually connect over USB. Advanced sound production and recording require an audio interface with multiple independent audio inputs and outputs. They may also have specialized ports such as XLR.

As technology continues to evolve, computers increasingly provide digital audio output. In such cases, HDMI and Bluetooth connections are digital-only and do not require a sound card. Instead, an external device such as a TV or Bluetooth headphones perform digital-to-analog conversion. However, basic sound cards will still be included in most computers because analog speakers and headphones remain widespread.

Sound card color code

The 3.5 mm jacks are color-coded so users can easily tell which port is for which channel. These colors include the following:

  • Pink. Microphone input.
  • Light blue. Line level input.
  • Lime green. Left and right stereo output or headphones.
  • Orange. Center and subwoofer output.
  • Black. Surround sound left and right output.
  • Grey. Surround sound rear left and right output.
  • Yellow. Digital output.

Learn the essentials of buying server hardware, including what you need to know about server motherboards.

This was last updated in June 2023

Continue Reading About sound card

  • innovation management

    Innovation management involves the process of managing an organization's innovation procedure, starting at the initial stage of ...

  • radical innovation

    Radical innovation is an invention that destroys or supplants an existing business model.

  • process mining

    Process mining is a technique that interprets logs from enterprise applications -- like customer resource management (CRM) and ...

  • employee resource group (ERG)

    An employee resource group is a workplace club or more formally realized affinity group organized around a shared interest or ...

  • employee training and development

    Employee training and development is a set of activities and programs designed to enhance the knowledge, skills and abilities of ...

  • employee sentiment analysis

    Employee sentiment analysis is the use of natural language processing and other AI techniques to automatically analyze employee ...

Customer Experience
  • customer profiling

    Customer profiling is the detailed and systematic process of constructing a clear portrait of a company's ideal customer by ...

  • customer insight (consumer insight)

    Customer insight, also known as consumer insight, is the understanding and interpretation of customer data, behaviors and ...

  • buyer persona

    A buyer persona is a composite representation of a specific type of customer in a market segment.