Audio Visual Glossary

Ambient Light: Level of illumination from natural lighting sources already existing in an environment.
Amplifier: A device which enables a sound signal to be amplified.
Boom: Adjustable support for positioning microphones or lighting fixtures.
CAT-5: A type of cable used in Ethernet networks. It is also known as simply a “patch cable.”
CD-ROM: A compact disk that can hold up to 700 Megabytes of data. Data can only be read from the disk, not erased or recorded over.
Dimmer: A device that controls the brightness of lights by controlling the voltage to the light.
Distortion: Unclear audio signal that results from giving too much power to a speaker or amplifier.
DVD-ROM: This is much like a CD-ROM except that it can store up to 12 times the amount of data; typically, 4.7GB-18GB.
Ethernet: A popular type of network.
Feedback: Regeneration of sound from audio speakers back through the audio source, causing a hum or high-pitched sound.
Flash Drive: USB driven removable storage device typically capable of storing 512MB to 4G of data. Also commonly called a thumb drive, memory stick or jump drive.
Fogger: An electrical device that creates clouds of artificial non-toxic fog. The fog can come in different colors or smells.
Follow Spot: Manually movable lighting instrument used to highlight and follow talent.
Front Screen Projection: Projection of an image onto the front surface of a light-reflective screen from a projector placed within or behind the audience.
Gels: Colored cellophane able to withstand high heat levels. Gels are placed in front of a lens to give the light a particular color.
Gobo: A small metal disc with an image cut into it that allows light to pass through and project the image onto a solid surface such as a wall, banner or projection screen.
Gooseneck: Flexible support attached to a podium or lectern which can be raised or lowered to suitable height and supports a microphone.
Harness: Bundle of cables.
High Definition (HD, High Def): A significantly clearer, higher resolution digital image than traditional formats.
House Board: Switch panel from which all electrical fixtures are operated.
In Sync: Sound and picture are synchronized or matched perfectly.
Keystoning: Distortion of a projected image that results when the lens is not directly aligned with the visual center of the screen.
Lavaliere: Small microphone that attaches to clothing.
Lectern: Support furniture for speaker’s notes and materials that can be placed on top of a table or stand.
LCD: Liquid Crystal Display. A display technology commonly used in laptop computers, flat panel computer monitors and flat screen TV’s.
Leko Light: Used for longer throw distances and creates a narrow beam of light.
LED: Light Emitting Diode
Lighting Controller: Controls the brightness of the lights by remotely controlling the dimmer. Also allows operator to pre-set scenes.
Light Tree: Contains a base with two pipes forming a T. Lights hang off of the crossbar.
Line Array: A group of sound-radiating devices that have been arrayed or “stacked up” in the vertical plane. Line array systems provide a highly consistent, predictable sound field that is ideal for covering medium to large audience areas.
Lumen: A measurement of light produced from a light source such as a projector (A 100 watt incandescent light bulb will output around 1500 lumens).
Masking: Draping around a screen to create a specific projected image.
Matte White: Smooth white vinyl front projection surface.
Mixer: Audio unit by which sound signals from all sources feed into one system; allows for dissimilar inputs (mic and line) to be combined and controlled into one output.
ParCan Light: Used for short throws and creates a wide beam of light.
Patch: Plug-in connection between two lines.
PIP: Picture-in-picture.
Pix Cart/Pixmobile: Rolling cart used for monitors, projectors, etc.
Pre-Con: Pre-convention meeting where the meeting planner and different vendors meet to review the purpose and details of an event.
Rear Screen Projection: Image projected on the back surface of a screen placed between the audience and the projector.
RF: Radio frequency. In video, this signal carries both audio and video-like commercial broadcasts.
Rigging: A term generally used to describe all systems used to support, move or fly scenery, lighting fixtures, drapery and other masking devices.
Riser: Platforms of various heights (12”-18”, 18”-24”, or 24”-36”) used to elevate the speaker or head table so they can be seen throughout the room.
Simultaneous Interpretation: Allows attendees to listen and understand proceedings in their own language.
Software: Applications that run on a computer. For example Microsoft Word, PowerPoint and Excel are types of software.
Striplights: Lighting instruments with a line of lamps, often with reflectors and color gels, used in color lighting.
Track Lighting: Lights attached along a rod-like metal track mounted on a ceiling or wall permitting flexible spot lighting and other lighting effects.
Turnaround/Turnover: Tear-down and reset of a room for one event or another.
Tweak: To make fine tuning adjustments.
Valance: Drape that is hung above the screen.
Wide Screen: Extra large display available in sizes up to 20'x60' that can be comprised of either one large image or several smaller PIP images.
Wings: Drape that extends from floor to ceiling on either side of the screen.