audio basics chapter 6. ch. 6 objectives explain the function of audio for television identify the...

Audio Basics

Chapter 6

Television Production & Broadcast Journalism, 2nd Ed.

Ch. 6 Objectives

Explain the function of audio for television

Identify the most common use of each type of microphone

Understand the importance of the pick-up pattern classification when selecting a microphone

Recall the appropriate VU meter readings for both an analog audio system and a digital audio system


Ch. 6 VocabularyAutomatic gain control (AGC)Background soundBoomBoundary micCondenser micDynamic micFishpole boomHigh impedance (HiZ)Lapel mic (lav)Low impedance (LoZ)Mic levelNatural (nat) sound

Off-camera narrationOmni-directional micOn-camera narrationParabolic reflector micPick-up patternRibbon micRoom toneShotgun micUni-directional micVoice trackWireless mic


The Functions of Sound for Television

Functions of sound for television:

Voice track

Music and sound effects

Environmental sound

Room tone


Voice Track

Primary means of getting a message to the viewer

Considered the most necessary audio of a program

Sound created through dialogue or narration


Two Forms of Narration

On-camera narration – viewer sees the narrator speaking

Off-camera narration – viewer hears but does not see the narrator

Also called voiceover (VO)

Narrator may be:

Reporter

On-the-street eyewitness


o Automatic dialogue replacement (ADR) – see Production Note on p. 133

o Music and sound effects help set the mood and enhance the action of a program.

o Complete silence is artificial and should rarely, if ever, be found in a TV program.

o Care must be taken to prevent the volume of environmental sound from becoming distracting.


Environmental Sounds

1. Background sound – environmental sound that is not the most important sound in a shot

Must not overpower the foreground sound in a shot


2. Natural (nat) sound – environmental sound that is important to the topic of the story

May be the most important sound in the shot

Usually captured on B-roll, either before or after the shot containing the voice track

Nat sound is environmental sound that helps call attention to what a reporter is saying

It entices the viewer to continue paying attention to the story

Only environmental sound that supports the story


Room Tone

The sound present in a room, or at a location, before human occupation

The “sound of silence” in the shooting environment

Record at least three minutes of existing environmental sound

Useful when editing

Environmental (room tone) sound may be used to cover unwanted sounds in the background of a scene that were not noticed while shooting

Less noticeable audio edit than if true silence were used


Sound Frequency

Three groups of sound frequency:

1. Low-frequency (bass guitar, drum & tuba; bass vocals)

2. Mid-range (trumpets, clarinets, French horns; alto & tenor vocals)

3. High-frequency (flutes & piccolos; soprano vocals)


MicrophonesMicrophone – the piece of equipment that picks up sounds in the air and sends them to the mixer or recorder

How microphones work:

1. Sound waves in the air hit a thin surface inside the mic (generating element or diaphragm) which vibrates

2. The vibration moves a tiny wire back and forth through a magnetic field creating an electrical signal

3. This electrical signal is sent through the mic cable to an amplifier or recorder


Mics can be differentiated by examining the frequencies of sound each best captures

Some mics pick up certain frequencies of sound better than others

Audio engineer’s goal – match the right mic to the right frequencies of sound

All microphones are not created equal – typically get what you pay for

Low-cost gear often yields results that are less than satisfactory


Wired & Wireless Mics

Refers to how the signal gets from the mic to the recorder

Wired mic - attached to the recorder by a cable

Very reliable

Greatest disadvantage—the cables


Wireless mic - short cable that runs from the mic to a radio transmitter

Transmitter sends the signal through the air, via a radio wave, to a receiver that is on or near the recorder

Receiver picks up the signal and sends it through a short cable to the recorder

Wireless mics not the best choice for all applications, however

Primary advantage – freedom of movement

Disadvantage – prone to interference from other wireless devices at or near the same frequencies

Always keep a backup wired mic available


Dynamic Microphones

Very rugged type of mic that has good sound reproduction ability

Designed to pick up sounds best in normal speaking voice frequencies

Not designed to mic musical instruments or accompanying vocals

Do not pick up high- and low-frequency sounds as effectively as mid-range sounds of speech


Condenser Microphones

Mic that requires an external power supply (usually a battery) to operate

Can pick up a greater range of sound frequencies than dynamic mics

Good condenser mics are usually more expensive


Ribbon MicrophonesMost sensitive of all mic types

In television applications, most commonly placed on a talk show host’s desk

Now primarily used in music recording studios

Expensive disadvantage – fragility of generating element (diaphragm)

Often must use a “pop filter” which protects the mic from explosive “t” and “p” sounds, catches moisture and rushes of air before they hit the diaphragm


Non-Professional Microphones

Microphone built into low-end camcorders

Should not be used in professional recording scenarios

Very limited pick-up range

Often produces audio that sounds like the person speaking has a bucket over his head

Picks up the grinding sound of the zoom lens motor, the rubbing or knocking sounds of the operator’s fingers and hands, and the sound of the operator breathing


Specialized MicrophonesBoundary mic

Most commonly a condenser type mic

Becoming the most common way to mic an entire stage or large room

Parabolic reflector mic

Very sensitive mic that looks like a satellite dish with handles

Sensitivity of electronic parts directly related to the cost

Often seen on the sidelines of professional football games


Pick-Up Pattern

Refers to how well a mic “hears” sounds from various directions

Omni-directional mic – pick-up pattern that captures sound from nearly every (omni) direction equally well

Uni-directional mic (cartioid) – pick-up pattern picks up sound from primarily one (uni) direction


In a noisy environment, a directional mic is a better choice for a narrator or reporter

The viewer may have a difficult time separating the talent’s voice from the background sounds if an omni-directional mic is used

Hypercardioid mic – narrower and longer pick-up pattern than a cardioid mic

Supercardioid mic – even narrower pattern

Shotgun mic – even more directional still (parabolic reflector mic is a shotgun mic)


Mics on the Set

Hand-held microphone

Designed to be held in the hand

Can be placed on a stand or boom

Sometimes referred to as a stick mic


Boom

A pole that is positioned over the set with a microphone attached to the end of the pole

The goal is to get the mic as close to the talent as possible without dipping the mic into the top of the picture

Fishpole boom – type of boom that must be physically held over the heads of talent

Lapel mic (lav or lavalier)

Smallest mic worn by talent

Attached about 6 inches from the mouth

Wired under clothing


Guidelines for Handling Mics

Never blow into a microphone

Do not shout into a microphone

Never let anyone put their lips directly on the mic

Do not slap the head of the microphone to hear the muffled thump through the speakers

Do not exhale directly into or inhale through the mic

Never swing a mic by its cord


Proper Use of Microphones

Do not place lips directly on the surface of the mic

When using a hand-held, hold the mic firmly and keep hand and fingers still

Get the mic close enough to your subject in an interview

When interviewing a child, get on his/her level

Never place an audio or mic cable beside an electrical cable

Electrical cables produce magnetic fields which can cause interference in the audio signal


ImpedanceIn television, a microphone’s purpose is to create a signal that is sent through a cable to be recorded.

There are two kinds of signals that mics can send:

High impedance (HiZ) – a typically inexpensive, low-quality mic that cannot tolerate a cable longer than 8’

Low impedance (LoZ) – high-quality, more costly mic that can tolerate long cable lengths


Three Levels of Audio

Mic level – the level of audio that comes from a microphone

Designed to be sent to the “mic in” on a recorder or mixer

Line level – level of audio between pieces of audio equipment

Example – the level of audio going from the output of a CD player to the input on an amp

Power level – the audio level from the output on an amplifier to the speaker


Mixers

Mic mixer – combines only the microphone signals into a single- or dual-channel sound signal

Audio mixer – designed to take the sounds from a variety of sources such as mics, a CD player, or tape player, and combine them into a single sound signal that is sent to the recorder


Automatic Gain Control

A circuit found on most consumer video cameras that controls the audio level during the recording process

Works best when it is part of a digital camcorder as opposed to an analog recording situation


Critical Note

It is critically important for whoever is recording the audio to wear a good set of headphones that cover the entire ear

This is the only way to accurately monitor the quality of the audio being recorded

audio basics chapter 6. ch. 6 objectives explain the function of audio for television identify the...

Documents

sound of silence

important sound

program sound

foreground sound

sound present

television functions

volume of environmental

environmental room tone