Operation Manual

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Chapter 18: Digital audio glossary
TheglossaryisyourguidetounfamiliartermsincommonaudioworkflowsandmultipleAdobeAuditionfeatures.
If you don't find a term here, search for it in Help to find a feature-specific definition.
Common audio terms
A
ADAT A digital 8-track tape deck manufactured by Alesis Corporation that is very popular in recording studios.
ADC (analog-to-digital converter) The hardware that converts an analog audio or video signal into a digital signal
that you can process with a computer.
aliasing NoisethatoccurswhenahighfrequencysoundexceedstheNyquistFrequencyforagivensamplerate.(See
“Nyquist frequency” on page 277.) Most analog-to-digital converters prevent aliasing by filtering out sounds above
the Nyquist Frequency.
amplitude Amplitude represents the volume of an audio signal. A waveform’s amplitude is measured by its distance
from the center line, which represents an amplitude of 0. There are different standards for measuring amplitude, but
the decibel (dB) is the most common. (See “decibel (dB)” on page 274.)
analog recording Traditional audio recording with devices such as magnetic tape machines and vinyl records.
Analog audio recording consists of a continuous curve, as opposed to digital recording, which consists of discrete
samples.
ASIO (Audio Stream In/Out) A standard for low-latency drivers, created by Steinberg Media Technologies.
attack The first part of the sound that you hear. Some sounds (like pianos and drums) have a very fast attack; the
loudestportionofthesoundoccursveryquickly.Asoundwithaslowattackrate(suchasasoftstringsection)slowly
increases in volume.
attenuate To reduce volume or signal level.
automation The process of recording volume, pan, and effects changes during a mix, and perfectly reproducing
those changes every time a mix plays. (See “Techniques for automating mixes” on page 203.)
B
band pass filter A filter that allows some audio frequencies to pass through unchanged.
beats per minute (bpm) Musical tempo, which is defined by the number of beats that occur every 60 seconds.
bit depth (or bit resolution) The number of bits used to represent audio amplitude. For example, 8-bit resolution
provides 256 possible amplitude levels and a 48 dB dynamic range; 16-bit resolution provides 65,536 levels and a 96
dB range. Adobe Audition supports up to 32-bit resolution with 4,294,967,296 possible levels. For the best audio
quality, remain at 32-bit resolution while transforming audio in Adobe Audition, and then convert to a lower bit
depth for output.
brown noise Brown noise has a spectral frequency of 1/f^2, so it emphasizes low-frequency components, resulting
in thunder- and waterfall-like sounds. Brown noise follows a Brownian motion curve, in which each sample in a
waveform contains a mixture of predefined and random frequency components.