broadcasting chatpter 6 audio basics

Voiceover

Program narration in which viewers hear the narrator's voice but do not see them on camera.

Automatic Gain Control (AGC)

An internal circuit in consumer video cameras that automatically adjusts and balances audio recording levels.

Boom

A long, adjustable pole held above a set with a microphone attached to the far end.

Potentiometer

A rotary knob or fader slider used to regulate incoming audio signal levels on a console or mixer.

On-camera narration

Program commentary delivered by talent who is visible directly on screen.

Boundary microphone

A flat, low-profile mic designed to rest on a surface to capture sound across a stage or large room.

Pick-up pattern

The directional perimeter indicating how effectively a microphone captures sound from different angles.

Parabolic reflector

A concave, bowl-shaped device that concentrates and captures distant audio with high sensitivity.

Background sound

Ambient environmental noise present in a location that is subordinate to the primary audio.

Room tone

The subtle ambient sound profile of an empty room or location before any action or dialogue begins.

Three basic sound-frequency groups

Low-frequency, mid-frequency, and high-frequency.

Audio feedback

A harsh screech or howl occurring when a microphone picks up sound output from a loudspeaker broadcasting that same mic's signal.

Lavalier microphone

The smallest clip-on microphone type designed to be attached directly to talent's clothing.

Line level

The standard audio signal voltage utilized for transferring audio between electronic processing devices.

High-impedance microphones

Low-cost, consumer-grade mics that suffer high signal loss and cannot support cable runs beyond $8\,\text{ft}$.

Voice track primary role

Serves as the central method for communicating the core spoken message directly to the audience.

Natural sound (nat sound)

Environmental audio that directly relates to and enhances the story being presented.

Ribbon microphone generating element

A corrugated, ultra-thin strip of metallic foil or coated film suspended within a magnetic field.

Preferred microphone pattern for noisy environments

A directional microphone, which suppresses unwanted ambient noise in favor of the speaker's voice.

Digital VU meter guideline

Readings must remain safely below $0\,\text{dB}$ full scale, as signals crossing into positive territory cause digital clipping distortion rather than safely fluctuating between $-3$ and $+3$.

Audio placed beneath primary dialogue during editing

Natural sound (nat sound).

Wireless microphone broadcasting component

Transmitter.

Common external source of wireless mic interference

Baby monitors and other household wireless devices sharing neighboring radio frequency bands.

Dynamic microphone

A rugged transducer consisting of a diaphragm attached to a wire coil suspended inside a magnetic field.

Most sensitive television microphone type

Ribbon microphone.

Uni-directional pick-up pattern

A pickup response pattern engineered to capture sound primarily from a single direction.

Device that generates feedback when exposed to its own amplified output

Microphone.

Handheld microphone spacing technique

Resting the thumb knuckle against the sternum to secure a reliable, fixed distance to the mouth.

Power level

The amplified audio signal traveling from an amplifier output to drive passive loudspeakers.

Audio mixer

A console that blends audio signals from multiple input sources into a balanced composite output.