Sound on the Web

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Sound on the Web
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Using Sound on a Web Site

• Conveying information
• pronounce a word or describe a product
• Set a mood
• music to match the web page scene
• Capture attention a sound effect
• Explain a process
• Provide personal contact voice, laugh

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Physics of Sound cycles per second Hertz (Hz)
or KHz
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Sampled Sound

• Sound wave is digitized by sampling at twice the
  highest frequency
• Converted to a number representing the volume
  (amplitude)
• Stored in a computer file
• Can represent any sound
• called a wave file usually a file extension
  .wav
• Often compressed to reduce file size

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Sampled Sound
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Musical Instrument Digital Interface (MIDI)

• Not sampled includes a code representing --
• Musical note
• Loudness
• Length of time
• Type of instrument
• Not compressed
• Generated by a synthesizer
• File extension .mid

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Characteristics of sampled, compressed and Midi
files

• Sampled files are very large depending on the
  highest frequency being recorded and length of
  recording.
• voice less than 8 kHz sample 16kHz
• symphony orchestra 22 kHz sample 44 Hz, Mono
• Compressed sound is sampled sound processed to
  make the file smaller without sacrificing sound
  quality
• Midi are much smaller files but can represent
  only music

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Streaming Sound

• Played by user computer as it is received not
  downloaded
• saves bandwidth
• does not require storage space on user computer
• live event sounds
• prevent copying file

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Sound File Formats

• Link

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Preparing Sound for the Web Create a File

• Use pre-recorded sound
• Record from microphone
• Use text-to-sound synthesizer
• Edit mix sounds, cut, cut-and-paste, add
  effects (Audacity)
• Record musical instrument sounds from synthesizer
  (cannot be edited in computer)

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Download a Sound File

• An example web site -- http//simplythebest.net/so
  unds/
• Sometimes the file may be a Zip file
• compressed
• combine several files in one
• Zip files are shown as a folder with a zipper on
  it. It can be
• automatically unzipped by double clicking on
  the folder and
• selecting extract all files.

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Text To Speech Conversion

• http//www.research.att.com/ttsweb/tts/demo.php
  (note different voices)
• Audacity has a built-in converter

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Including Sound on Web Page(Same procedure as
with a movie)

• Passive plays automatically
• Active requires user action
• Embedded Media -gt Plugin
• Linked hyperlink to audio file sound file
  opens in separate window

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Autoplay True, False Controller True,
False Loop True, False
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Audacity sound utility