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

  • local area network (LAN)

    A local area network (LAN) is a group of computers and peripheral devices that are connected together within a distinct ...

  • TCP/IP

    TCP/IP stands for Transmission Control Protocol/Internet Protocol and is a suite of communication protocols used to interconnect ...

  • firewall as a service (FWaaS)

    Firewall as a service (FWaaS), also known as a cloud firewall, is a service that provides cloud-based network traffic analysis ...

  • identity management (ID management)

    Identity management (ID management) is the organizational process for ensuring individuals have the appropriate access to ...

  • single sign-on (SSO)

    Single sign-on (SSO) is a session and user authentication service that permits a user to use one set of login credentials -- for ...

  • fraud detection

    Fraud detection is a set of activities undertaken to prevent money or property from being obtained through false pretenses.

  • project scope

    Project scope is the part of project planning that involves determining and documenting a list of specific project goals, ...

  • core competencies

    For any organization, its core competencies refer to the capabilities, knowledge, skills and resources that constitute its '...

  • change management

    Change management is a systematic approach to dealing with the transition or transformation of an organization's goals, processes...

  • recruitment management system (RMS)

    A recruitment management system (RMS) is a set of tools designed to manage the employee recruiting and hiring process. It might ...

  • core HR (core human resources)

    Core HR (core human resources) is an umbrella term that refers to the basic tasks and functions of an HR department as it manages...

  • HR service delivery

    HR service delivery is a term used to explain how an organization's human resources department offers services to and interacts ...

Customer Experience
  • martech (marketing technology)

    Martech (marketing technology) refers to the integration of software tools, platforms, and applications designed to streamline ...

  • transactional marketing

    Transactional marketing is a business strategy that focuses on single, point-of-sale transactions.

  • customer profiling

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