Chapter 6

Sound

MELJUN CORTESMELJUN CORTES

Chapter Objectives

• Explain the basic principles of sound• Describe the different categories of sound• Explain how sound can be used in different types of

Web sites• Describe the roles and responsibilities of the Audio

Specialist• Describe several factors that determine sound quality

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Chapter Objectives

• List some different sources of digital audio• List and explain the steps in producing digital audio• Explain the difference between destructive and non-

destructive sound processing• List and describe the different sound tools available for

producing and editing Web audio• List the most popular audio file formats found on the

Web and explain some of their key features

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Introduction

Acquire knowledge and pleasure through our sense of hearing

Sound sets the mood/tone If not properly incorporated, may do more

harm than good

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Basic Principles of Sound

Waveform Amplitude

measured in decibels

Frequency measured in hertz

(Hz)/kilohertz(kHz)

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Types of Sound

Analog Digital

Also called audio Acquired through sound sampling/digitizing

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Categories of Sound

Content sounds Provide information

Ambient sounds Reinforce message and set the mood

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Uses of Sound

Online Training and Education

Advertising and E-commerceEntertainment and Games

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Audio Specialist

Records and process sound

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Sound Quality

Rate Number of waveform

samples/second 11 kHz – 44 kHz

ResolutionNumber of bits used to sample sound8-bit and 16-bit

Mono, Stereo, Surround (3D) SoundDownloaded v. Streamed

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Digital Audio Sources

Clip audio Record your own

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Producing Digital Audio

Planning Recording Processing Assembling Delivering

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Planning

Include in: Flowcharts Storyboards Scripts

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Recording

Microphone uses analog-to-digital (ADC) converter

Digital audiotape (DAT)Hire talented actors/narratorsMIDI

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Processing

Destructive v. Non-destructive Editing and Mixing

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Assembling

Linked Embedded

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Delivering

Sound Card Speakers – digital-to-analog (DAC)

converter

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Digital Audio Software

Bias Sonic Foundry Digidesign Shareware

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Bias

Peak - Mac Ideal for manipulating single-sound files Change volume, pitch, tempo Support for a variety of file formats including

Red Book Special Effects

Fades, envelopes, equalizer, echo/reverberation, pitch shift, normalize, backward and tempo

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Sonic Foundry

Sound Forge – Windows Set sample rate, resolution, size Record Copy, paste, mix, crossfade Synchronize using SMPTE timecode

Vegas Multitrack recording

Acid Multitrack and supports MIDI

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Digidesign

Pro Tools – cross platform Complete

package

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Shareware

Cool Edit Mixman

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File Formats

AIFF/AIF AU DCR MIDI

MP3 QuickTime (MOV) Real (RAM, RM, G2) WAV

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Compression

Variety of schemes MP3

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