tags: music mus-407 electroacoustic computer digital audio
Digital Audio
Digital audio is the representation of [sound] in a digital realm. Digital audio represents sound as a finite sequence of discrete values within an [audio signal], with each value representing a measurement of air pressure at a given point in time.
Key Terms
[sampling]: the process of periodically measuring the [amplitude] of an analog signal and assigning a digital value to each measurement
[sample rate]: number of samples taken per second
[quantization]: the process of approximating the measured analog value to the closest digital value
[bit depth]: the number of discrete digital values available for quantization (also called sample resolution or sample width)
ADC: analog-to-digital converter
DAC: digital-to-analog converter
sampling theorem: publication on the mathematical limitations of discretization of continuous signals
- coined by Harry Nyquist, 1928
- also called [Nyquist Theorem] or Shannon-Nyquist Theorem
[pulse code modulation (PCM)]: specification for computer digitization of continuous signals
Sampling (disambiguation)
Sampling can have different meanings, depending on context.
- Using a significant portion of an existing work as a component in a new work
- Recording individual sound units from a musical instrument or other sound source, typically mapped to physical controls on a [midi] device and played back (see: [Sampling (composition)])
- Taking periodic measurements of an analog signal (see: [Sampling (signal processing)])
Digital Audio Standards
Across the commercial audio industry, there are [digital audio standards] to standardize audio file formats.
File Formats
There are a number of [file formats] in which digital audio can be stored.
Sources
- MUS 407 Computer Music and Digital Audio