ADSR
Attack, Sustain, Decay, Release. The four defined areas of a waveform.
Acoustics
Pertaining to sound; usually refers to the specific characteristic sound in a particular place (e.g. cathedral acoustic; concert hall acoustic; listening room acoustic etc).
Audio
A term used to describe sounds within the range of human hearing. Also used to describe devices which are designed to operate within this range.
CD Ripper/Grabber
A software program that transfers the cdda file from an audio CD into a computer format such as AIFF or WAV.
Chorusing
An processing effect that adds phase variations to a sound. Chorus adds a swirling property to a sound that it is applied to, thickening the sound.
Compact Disc
The first commercially available digital audio playback format. Software is a 12cm diameter single sided silver disc containing digitally encoded signal to a 44.1kHz, 16-bit standard. Optical playback is by means of laser beam.
Compression
A measure of the dynamic range of a signal. A compressed (or reduced) dynamic range may be required of some broadcast signals to prevent overload during some radio transmissions.
Compressor/Limiter
A device that that controls the dynamic range of a signal. It can be used to compress a whole signal (compressor mode) or just keep a signal from going above a certain volume level (limiter mode.) Too much compression can crush the dynamics out of a signal and make it sound flat (ala AM radio) Too much limiting can make the siganl sound clipped, or distorted.
Delay
The creation of a time shift in the playing of a file. Combining multiple time shifts with reverb and a fade out creates echo.
Equalization (EQ)
A process in which the frequency characteristic of an audio signal is changed by increasing (boosting) or decreasing (cutting) the amplitude of certain frequency ranges in relation to others.
Feedback
Acoustic or structure-borne vibrations that interfere with the operation of audio equipment. The best example is where a microphone gets too close to a speaker. A loop of sound may be created resulting in high frequency instability. In other words you get a high pitch whine and that's a bad thing.
Foley
Added Sound Effects
Format
The type of file a siganl is save as. Audio can exist on the computer in several formats. Mostly WAV (Windows Audio Video) on Windows machines and AIFF (Audio Interchange File Format) on Macintosh's. The most popular format (right now) is the MP3 format (MPEG-2 Layer-3). MP3 is a compressed format, usually 8-10 times smaller than the uncompressed WAV version of the same item (and unfortunately a format that slices all high end of the spectrum.)
Looping
The process of recording voices to match the mouth movments on existing video or film
Music Bed
Music that accompanies video. Often used in the background. Can be used to heighten emotional response from the viewer.
Noise Reduction
A process or device capable of bringing down the level of the background noise in relation to the actual signal source. Systems like DBX, Dolby, and others can use electronic means to reduce the hiss in a signal. It would take a whole page and lecture to explain how most noise reduction works, so lets just say it's magic.
Reverb
Reverb (short for reverberation) is the acoustic environment that surrounds a sound. Natural reverb exists everywhere. Whether the space being described is a bathroom or a gymnasium, the essential characteristics remain the same.
Reverb is composed of a series of tightly-spaced echoes. The number of echoes and the way that they decay play a major role in shaping the sound that you hear. Many other factors influence the sound of a reverberant space. These include the dimensions of the actual space (length, width, and height), the construction of the space (such as whether the walls are hard or soft and whether the floor is carpetted), and diffusion (what the sound bounces off of).
(Yes, Martin did cut and paste this one.)
Sampling Rate
The number of times per second a computer 'reads and records' a signal value, measured in hertz (hz.) The best example is that audio CDs have a smapling rate of 44.1 khz (44100 hz.)
Signal Processing
A generic term meaning any kind of (analogue or digital) treatment of a signal, intending to change the characteristic of the signal in some desired way. Typical signal processing applications are dynamic processing, equalization or noise reduction.
Streaming audio
A concept for communicating audio data over a network connection such as the Internet. In streaming audio, the complete audio file is not transferred to the client before it is played back. Instead, the data transfer will take place at a rate that (hopefully) exceeds the rate needed for continuous playback of the audio material. This means the client reproduces the audio "on line", without having to wait for the complete audio block to be transmitted. Streaming audio is by its nature sensitive to communication performance. If the consumption rate of the streaming audio is close to the limits of the communication line, there is a definite risk for unwanted interruption of the audio, due to lack of audio data.
|
