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 - Noise that occurs when a high frequency sound exceeds the Nyquist Frequency for a given sample rate. 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.
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 loudest portion of the sound occurs very quickly. A sound with a slow attack rate (such as a soft string section) 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.
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.
Bus - In hardware mixers, a channel that lets you combine several other channels and output them together. In Adobe Audition’s Multitrack View, you can similarly use software buses to combine several tracks.
Click Track - An audio track comprised of clicks that occur on the beat, like a metronome. Click tracks are often used at the beginning of a session to provide timing information for musicians and then removed from the session before mixing down.
Clip - A visual representation of individual audio, video, or MIDI files in Adobe Audition’s Multitrack View.
Clipping - In digital audio, distortion that occurs when the amplitude of a signal exceeds the maximum level for the current bit depth (for example, 256 in 8-bit audio). Visually, clipped audio produces broad flat areas at the top of a waveform. If you experience clipping, lower the recording input or the source output levels.
Codec - (compressor/decompressor) An abbreviation for the data compression schemes used by the ACM, AVI, MPEG, and QuickTime formats and the analog-to-digital converters on some sound cards. (Note that codecs only compress file size; to compress audio amplitude, apply a compressor effect.)
Compressor - An effect that reduces dynamic range by lowering amplitude when an audio signal rises above a specified threshold. For example, a compressor can compensate for variations in level caused by a vocalist...