Audio Basics

1. Audio Basics Chapter 6

2. 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

3. Television Production & Broadcast Journalism, 2nd Ed. Ch. 6 Vocabulary • Automatic gain control (AGC) • Background sound • Boom • Boundary mic • Condenser mic • Dynamic mic • Fishpole boom • High impedance (HiZ) • Lapel mic (lav) • Low impedance (LoZ) • Mic level • Natural (nat) sound • Off-camera narration • Omni-directional mic • On-camera narration • Parabolic reflector mic • Pick-up pattern • Ribbon mic • Room tone • Shotgun mic • Uni-directional mic • Voice track • Wireless mic

4. Television Production & Broadcast Journalism, 2nd Ed. The Functions of Sound for Television • Functions of sound for television: • Voice track • Music and sound effects • Environmental sound • Room tone

5. Television Production & Broadcast Journalism, 2nd Ed. 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

6. Television Production & Broadcast Journalism, 2nd Ed. 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

7. Television Production & Broadcast Journalism, 2nd Ed. • Automatic dialogue replacement (ADR) – see Production Note on p. 133 • Music and sound effects help set the mood and enhance the action of a program. • Complete silence is artificial and should rarely, if ever, be found in a TV program. • Care must be taken to prevent the volume of environmental sound from becoming distracting.

8. Television Production & Broadcast Journalism, 2nd Ed. Environmental Sounds • Background sound– environmental sound that is not the most important sound in a shot • Must not overpower the foreground sound in a shot

9. Television Production & Broadcast Journalism, 2nd Ed. • 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

10. Television Production & Broadcast Journalism, 2nd Ed. 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

11. Television Production & Broadcast Journalism, 2nd Ed. Sound Frequency • Three groups of sound frequency: • Low-frequency (bass guitar, drum & tuba; bass vocals) • Mid-range (trumpets, clarinets, French horns; alto & tenor vocals) • High-frequency (flutes & piccolos; soprano vocals)

12. Television Production & Broadcast Journalism, 2nd Ed. Microphones • Microphone – the piece of equipment that picks up sounds in the air and sends them to the mixer or recorder • How microphones work: • Sound waves in the air hit a thin surface inside the mic (generating element or diaphragm) which vibrates • The vibration moves a tiny wire back and forth through a magnetic field creating an electrical signal • This electrical signal is sent through the mic cable to an amplifier or recorder

13. Television Production & Broadcast Journalism, 2nd Ed. • 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

14. Television Production & Broadcast Journalism, 2nd Ed. 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

15. Television Production & Broadcast Journalism, 2nd Ed. • 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

16. Television Production & Broadcast Journalism, 2nd Ed. 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

17. Television Production & Broadcast Journalism, 2nd Ed. 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

18. Television Production & Broadcast Journalism, 2nd Ed. Ribbon Microphones • Most 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

19. Television Production & Broadcast Journalism, 2nd Ed. 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

20. Television Production & Broadcast Journalism, 2nd Ed. Specialized Microphones • Boundary 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

21. Television Production & Broadcast Journalism, 2nd Ed. 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

22. Television Production & Broadcast Journalism, 2nd Ed. • 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 • Hypercardioidmic – narrower and longer pick-up pattern than a cardioid mic • Supercardioidmic – even narrower pattern • Shotgun mic – even more directional still (parabolic reflector mic is a shotgun mic)

23. Television Production & Broadcast Journalism, 2nd Ed. 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

24. Television Production & Broadcast Journalism, 2nd Ed. • 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

25. Television Production & Broadcast Journalism, 2nd Ed. 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

26. Television Production & Broadcast Journalism, 2nd Ed. 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

27. Television Production & Broadcast Journalism, 2nd Ed. Impedance • In 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

28. Television Production & Broadcast Journalism, 2nd Ed. 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

29. Television Production & Broadcast Journalism, 2nd Ed. 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

30. Television Production & Broadcast Journalism, 2nd Ed. 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

31. Television Production & Broadcast Journalism, 2nd Ed. 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