AVIXA Certified Technology Specialist (CTS): key terms

Flashcards for this exam AVIXA Certified Technology Specialist (CTS) guide Class dates

• Acoustic Echo Cancellation (AEC)DSP processing that removes far-end audio picked up by local microphones so remote participants do not hear their own voices.Intermediate
• AES3The professional standard for transmitting two channels of digital audio over balanced 110-ohm cable with XLR connectors.Intermediate
• AES67An AES interoperability standard for high-performance audio over IP using RTP, PTPv2 and common audio formats.Advanced
• AliasingDistortion created when frequencies above half the sampling rate are sampled and appear as false lower frequencies.Intermediate
• As-Built DocumentationFinal drawings and records that show how an AV system was actually installed, including signal flow, rack elevations and labels.Foundational
• Assistive Listening System (ALS)A system that delivers audio directly to people with hearing loss through FM, infrared or induction loop technology.Intermediate
• Audio Clock SynchronizationEnsuring all digital audio devices sample at exactly the same rate from a shared reference to avoid clicks and dropouts.Advanced
• Audio Digital Signal Processor (Audio DSP)A processor that performs digital audio functions such as mixing, EQ, dynamics, AEC, routing and delay in AV systems.Intermediate
• Audio Noise FloorThe level of background noise in a system or room when no intended signal is present.Foundational
• Audio Video Bridging (AVB)A set of IEEE 802.1 standards that provide time-synchronized, low-latency, reserved-bandwidth streaming over Ethernet.Advanced
• Automatic Mixer (Automixer)A mixer that automatically turns up active microphones and attenuates inactive ones to reduce noise and feedback.Intermediate
• AV Control SystemA system of processors, touch panels and keypads that operates AV devices through IR, RS-232, relays and IP commands.Foundational
• AV Performance VerificationSystematic testing of an installed AV system against standards and design intent, as defined in ANSI/INFOCOMM 10:2013.Intermediate
• AV-over-IP (AVoIP)Distribution of audio and video signals as packets over standard Ethernet networks using encoders and decoders.Intermediate
• Balanced AudioAudio transmission using two signal conductors of opposite polarity plus a shield, allowing noise rejection at a differential input.Foundational
• Bit DepthThe number of bits used to represent each digital audio sample, determining resolution and dynamic range.Foundational
• Boundary MicrophoneA microphone mounted flush with a surface such as a table or ceiling to use the boundary for increased sensitivity.Foundational
• Bring Your Own Meeting (BYOM)A room design in which users run the meeting from their own laptop while using the room's camera, microphones and display.Foundational
• Chroma SubsamplingReducing color resolution relative to brightness to save bandwidth, written as 4:4:4, 4:2:2 or 4:2:0.Intermediate
• Cisco Room KitA family of Cisco video conferencing systems for meeting rooms, combining codec, cameras, microphones and speakers.Foundational
• ClippingDistortion that occurs when a signal exceeds the maximum level a device can reproduce, flattening the waveform peaks.Foundational
• CodecA coder-decoder algorithm that converts analog audio or video to compressed digital form and back.Foundational
• Color TemperatureA measure in kelvin of the color characteristics of light, from warm (lower K) to cool (higher K).Intermediate
• Condenser MicrophoneA sensitive microphone that uses a charged diaphragm and backplate capacitor, requiring phantom power or a battery.Foundational
• Constant-Voltage Audio DistributionA loudspeaker system using 70 V or 100 V lines with transformer taps so many speakers can share one amplifier channel.Intermediate
• Contact ClosureA simple control method that opens or closes a dry electrical contact, used for screens, lifts, shades and sensors.Foundational
• Content SharingSending a presentation, screen or document as a separate stream in a meeting, wired or wirelessly.Foundational
• Continuous Presence (CP)A conference layout that shows multiple participants on screen at once, such as a grid or active speaker plus thumbnails.Foundational
• Contrast RatioThe ratio of the brightest white to the darkest black in an image, which in a real room is dominated by ambient light.Intermediate
• DanteAudinate's widely used audio-over-IP technology that carries many channels of low-latency digital audio over standard Ethernet.Intermediate
• Decibel Unit dBuA decibel unit for audio voltage referenced to 0.775 volts RMS, used for professional line levels.Intermediate
• Direct Input Box (DI box)A device that converts unbalanced high-impedance signals to balanced low-impedance mic-level signals for long runs.Intermediate
• Direct-View LED Display (dvLED)A display built from tiled modules of red, green and blue LEDs that emit light directly, with no LCD or backlight.Intermediate
• Display Image Size for 2D Content in Audiovisual Systems (DISCAS)The ANSI/AVIXA V202.01 standard for calculating display image size based on viewing distance and content type.Advanced
• Dynamic MicrophoneA rugged microphone that generates signal by moving a coil within a magnetic field, needing no external power.Foundational
• Dynamic RangeThe ratio in decibels between the loudest undistorted level and the noise floor of a system or signal.Intermediate
• Dynamics ProcessingProcessing that changes a signal's level based on its amplitude, including compressors, limiters, expanders and gates.Intermediate
• EqualizationAdjusting the level of specific frequency ranges in an audio signal to correct tonal balance or room problems.Foundational
• Extended Display Identification Data (EDID)Data a display sends to a source describing its supported resolutions, timings, color formats and audio capabilities.Intermediate
• Far-End Camera Control (FECC)The ability for a participant to pan, tilt and zoom a camera at the remote site during a video call, using H.224/H.281.Advanced
• FeedbackA howl or squeal caused when loudspeaker sound re-enters a microphone and is amplified repeatedly in a loop.Foundational
• Frame Rate (fps)The number of complete video images displayed or transmitted per second, such as 30 or 60 frames per second.Foundational
• Frequency ResponseThe range of frequencies a device reproduces and how evenly, usually stated as a range with a tolerance in dB.Foundational
• Gain StructureSetting the gain at each stage of an audio system so signals stay well above the noise floor without clipping.Foundational
• Ground LoopAn unwanted current path formed when equipment is grounded at multiple points with different potentials, causing hum.Intermediate
• Group of Pictures (GOP)The sequence of video frames between key frames, made of I-frames, P-frames and optionally B-frames.Intermediate
• H.264 (AVC)The ITU-T and ISO video compression standard (MPEG-4 Part 10 Advanced Video Coding) used by most conferencing systems.Foundational
• H.265 (HEVC)High Efficiency Video Coding, the successor to H.264 that delivers similar quality at roughly half the bit rate.Intermediate
• HDBaseTA standard that carries uncompressed video, audio, Ethernet, control and power over a single category cable up to 100 m.Intermediate
• HeadroomThe difference in decibels between a system's nominal operating level and the level at which it clips.Foundational
• High Dynamic Range (HDR)Video formats that represent a wider range of brightness and color than standard dynamic range, using 10-bit or higher depth.Intermediate
• Infrared Control (IR)Controlling AV devices by sending modulated infrared light commands, either from a remote or from wired IR emitters.Foundational
• IPMXInternet Protocol Media Experience, an open AV-over-IP standard for pro AV built on SMPTE ST 2110 and AMWA NMOS.Advanced
• Jitter BufferA receive buffer that holds and reorders incoming voice packets to play them out at an even rate despite variable arrival times.Intermediate
• JPEG XSAn ISO/IEC 21122 low-latency, lightweight video codec offering visually lossless quality at moderate compression ratios.Advanced
• Keystone CorrectionAdjusting a projected image to correct the trapezoidal distortion caused when a projector is not perpendicular to the screen.Foundational
• Line LevelThe standard audio signal level between devices, +4 dBu for professional gear and -10 dBV for consumer equipment.Foundational
• Lip SyncThe alignment of audio with corresponding video so speech matches lip movement.Intermediate
• Loudspeaker ImpedanceThe nominal AC resistance of a loudspeaker, such as 4 or 8 ohms, which determines the load presented to an amplifier.Foundational
• Microphone ArrayA group of microphone elements whose signals are combined with DSP beamforming to form steerable pickup lobes.Intermediate
• Microphone Level (Mic level)The very low signal voltage produced by microphones, typically around -60 to -40 dBu, which needs a preamplifier.Foundational
• Microsoft Teams Rooms (MTR)Certified meeting room systems that run the Teams Rooms app on Windows or Android for one-touch Teams meetings.Foundational
• Multipoint Control Unit (MCU)A conference bridge that decodes, mixes and re-encodes audio and video from multiple participants into composite streams.Intermediate
• Needs AnalysisThe first phase of an AV project, identifying how clients will use the space, who the users are, and the required functions, budget and constraints.Foundational
• Network Device Interface (NDI)A Vizrt (formerly NewTek) protocol for low-latency video, audio and control over standard IP networks, common in live production.Intermediate
• Nit (cd/m2)A unit of luminance equal to one candela per square meter, used to specify display brightness.Foundational
• Nyquist TheoremThe rule that a signal must be sampled at least twice its highest frequency to be reconstructed accurately.Foundational
• Ohm's LawThe electrical relationship V = I x R, with power P = V x I, used to calculate voltage, current, resistance and power.Foundational
• One Button to Push (OBTP)A feature that shows a single Join button on a video device for meetings scheduled in its room calendar.Foundational
• Packet Loss Concealment (PLC)Techniques a receiving codec uses to hide missing voice packets by replaying or interpolating audio.Intermediate
• Pan-Tilt-Zoom Camera (PTZ)A camera that can be remotely moved horizontally (pan), vertically (tilt) and zoomed, often with stored presets.Foundational
• Phantom PowerDC voltage, typically +48 V, supplied by a mixer or preamp through balanced microphone cable to power condenser microphones.Foundational
• Pixel PitchThe center-to-center distance between adjacent pixels on a direct-view LED display, measured in millimeters.Intermediate
• Polar PatternThe directional sensitivity of a microphone or loudspeaker, such as omnidirectional, cardioid, supercardioid or figure-8.Foundational
• Potential Acoustic Gain (PAG)A calculation of how much gain a sound reinforcement system can provide before feedback, compared with needed acoustic gain.Advanced
• Progressive ScanA video format that draws every line of each frame in sequence, denoted by p, as in 1080p.Foundational
• Projection Screen GainA measure of how much light a screen reflects toward the on-axis viewer compared with a matte-white reference of 1.0.Intermediate
• Projector BrightnessThe light output of a projector, specified in ANSI lumens, which determines image visibility in ambient light.Foundational
• Proximity EffectThe increase in low-frequency response that occurs when a directional microphone is very close to the sound source.Intermediate
• Proximity PairingA method in which a client app detects a nearby video device through ultrasound and pairs with it for sharing and control.Intermediate
• Public Switched Telephone Network (PSTN)The worldwide circuit-switched telephone network operated by carriers, reached from enterprise systems through gateways or SIP trunks.Foundational
• Pulse Code Modulation (PCM)The method of digitizing analog audio by sampling, quantizing and encoding the signal as binary values.Foundational
• Reverberation Time (RT60)The time it takes for sound in a room to decay by 60 dB after the source stops.Intermediate
• Room CombiningAutomatically reconfiguring audio, video and control when divisible rooms are joined or separated by moveable walls.Intermediate
• RoomOSThe operating system on Cisco collaboration devices such as Room Bar, Room Kit, Board and Desk series.Intermediate
• RS-232 ControlSerial control of AV devices over a DB9 or terminal connection using transmit, receive and ground conductors.Foundational
• Sampling RateThe number of times per second an analog signal is measured when converted to digital, such as 8 kHz or 48 kHz.Foundational
• ScalerA device or function that converts a video signal from one resolution or aspect ratio to another to match a display.Foundational
• Serial Digital Interface (SDI)A SMPTE standard for uncompressed digital video over 75-ohm coaxial cable with BNC connectors, used in broadcast and live production.Intermediate
• Signal FlowThe path an audio, video or control signal takes from source through processing and distribution to destination devices.Foundational
• Signal QuantizationThe step in digitization that rounds each sample to the nearest discrete level, introducing small quantization error.Foundational
• SMPTE ST 2110A suite of SMPTE standards for carrying separate video, audio and ancillary data streams over IP networks in professional media.Advanced
• Software Defined Video over Ethernet (SDVoE)An AV-over-IP platform from the SDVoE Alliance that uses 10 Gigabit Ethernet for very low latency, high-quality video.Advanced
• Sound MaskingAdding engineered background sound to a space to reduce speech intelligibility and distractions, improving privacy.Intermediate
• Sound Pressure Level (SPL)The acoustic pressure of a sound expressed in decibels relative to 20 micropascals, the threshold of human hearing.Foundational
• Speaker LevelThe high-power amplified signal sent from a power amplifier to loudspeakers, from a few volts to tens of volts.Foundational
• Speaker TrackingCamera automation that uses microphone arrays and face detection to frame the active speaker automatically.Intermediate
• Speech Transmission Index (STI)A 0-to-1 objective measure of speech intelligibility through a sound system and room, defined in IEC 60268-16.Advanced
• TelePresenceHigh-quality video conferencing designed to create the feeling of being in the same room, often with life-size images.Foundational
• Three-Point LightingA lighting method using key, fill and back lights to illuminate a subject evenly and separate it from the background.Foundational
• Throw RatioA projector's throw distance divided by the image width, used to determine where to mount the projector.Foundational
• Unbalanced AudioAudio transmission using one signal conductor and a shield that also serves as the return, making it susceptible to noise.Foundational
• USB Video Class (UVC)The USB standard that lets cameras work with computers without custom drivers, used by conferencing cameras and video bars.Intermediate
• Video CompressionReducing video data by removing spatial and temporal redundancy and perceptually less important detail.Foundational
• Video ConferencingReal-time two-way or multipoint audio and video communication between participants in different locations.Foundational
• Video Matrix SwitcherA device that routes any of multiple video inputs to any of multiple outputs, often with scaling and EDID management.Foundational
• Video WallMultiple displays or LED modules tiled together and driven by a processor to appear as one large image.Foundational
• Voice-Activated Switching (VAS)A conference mode that shows the current active speaker full screen and switches as different participants speak.Foundational
• Wideband Audio (HD Voice)Voice transmission covering about 50 Hz to 7 kHz or more, roughly double the bandwidth of traditional narrowband telephony.Foundational
• Wireless Presentation SystemA system that lets users share laptop or mobile screens to a room display without cables, using a dongle or app.Foundational