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Audio Communications: Sound. Mr. Butler Communication Systems John Jay High School Wappingers Central School District UPDATED 11/2011. Why is it important to learn about sound?. Sound is becoming increasingly important when designing for new media and Internet.
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Audio Communications: Sound Mr. Butler Communication Systems John Jay High School Wappingers Central School District UPDATED 11/2011
Why is it important to learn about sound? • Sound is becoming increasingly important when designing for new media and Internet. • You don’t have to be a musician to be a sound designer, but familiarity with all types of audio is important.
Sound Frequency • Sound is composed of a complex set of waves. These waves vibrate at different frequencies. • High frequencies are defined and controlled by the TREBLE knob on your amplifier • Low frequencies are controlled by the BASS knob
Analog Audio Theory What is Analog Audio? • Analog means that the sound has been recorded on an analog medium, most likely tape • Analog also means that each copy is NOT going to be equal to the original.
Digital Audio Theory Advantages of Digital Audio • Each copy is EQUAL to the original, and there is no generation loss. • This is why the music business moved to CDs.
Frequency Range • For most professional applications, it is desirable to record the original sound in as high a quality as possible and then sample it down.
Frequency Range • The normal range of human hearing is 20 to 20,000 Hertz, or cycles per second. Only very high quality sound systems and headphones are capable of reproducing this range. • Small computer speakers are capable of reproducing a more limited range of frequencies.
Dynamic Range • Dynamic range is the degree to which the sound gets louder and softer. • The wider the dynamic range, the more natural a sound appears and he greater the emotional impact. • Most recording systems seek to have the widest dynamic range possible.
Formats • Sound use to come in only two media, tape and vinyl. Now, myriad formats are available, including CD and Minidisk. • Some common computer formats include MP3, AIFF, WAV.
MIDI • MIDI: Musical Instrument Digital Interface • MIDI was developed in the mid-1980s • Allows keyboard synthesizers talk to the computer. • Ringtones
Audio on the Internet • MP3 is a technology that created its own industry. • Fueled mainly by college students, MP3 was a quick way to exchange and share music over the Internet.
Audio Internet Formats • There are many different formats for audio on the Internet, but five of them are the most common. • MP3 • RealAudio • Windows Media Player • QuickTime • AIFF and WAV
MP3 • the file extension for MPEG Audio Layer-3, a set of standards for compressing and downloading audio files from the Internet. • Most popular format • Widely used for exchange music files • Good compression scheme • Typical size per song: 3 to 4 MB. • Although the legal issues are still being worked out, MP3 is here to stay.
QuickTime • Apple Computer Product • QuickTime recently converted to a streaming format • Before QuickTime, you had to download QuickTime files.
AIFF and WAV • AIFF stand for Audio Interchange File Format • WAV files are called “wave” files. Both are high-quality audio files, and both require a lot of memory. • If you want CD-quality sound, AIFF or Wav will deliver it.
References • Digital Creativity, “Techniques for Digital Media and the Internet”-Bruce Wands