Univ of MD, College of Arts and Humaniites: Digital Technology in the Arts and Humanities

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Sound File Formats and Specifications
http://www.arhu.umd.edu/technology/workshops/mmpublishing/dva-audiofileformats.html
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Sound File Formats and their Usage

File Format Example Uses Plug-in Support Helper Ap Extension Description

AIFF/AIFC
(Macintosh Audio Exchange)
Director Interactive Multimedia Application
Quicktime Movie Player
Quicktime Pro
Window Media Player .aif, .aiff, .aifc The Audio Interchange File Format (AIFF/AIFC) allows storage of monaural and multichannel sample sounds at various sample rates. Since it is an interchange format, it is easily converted to other fileformats. For these reasons, it is often used in high-end audio recording applications when storage space is not a concern. AIFF alone does not allow for compressed audio data.

WAVE
(Microsoft's
Windows Waveform) Powerpoint Presentation Quicktime Movie Player
Quicktime Pro
Windows Media Player .wav, .wave A proprietary format most commonly used on Windows-based PCs. This format supports monaural and multichannel samples and a variety of sample rates, just like AIFF.

Real Audio Streamed Audio on a WebPage Real Player Real Player .RA, .RAM Real audio used for Streaming media which is useful when dealing with long audio tracks which are very large files.

MIDI Background Music for a Web Page Quicktime Movie Player
Quicktime Pro .midi,.mid MIDI files store musical notes that can then be playedback by a synthesizer (MIDI instrument or computer's sound card).

Quicktime Powerpoint Presentation Quicktime Movie Player
Quicktime Pro .mov QuickTime, software that allows you to play and edit various types of media on your computer, includes extremely efficient compressorswhich allow streaming of video, audio and photographic virtual reality.

MP3
(MPEG 2, Layer 3 ) WebPage Quicktime Movie Player
(More on players) .mp3 High quality but small file sizes. Quicktime now supports MP3 files.

Digitizing Audio
Large sound files result in higher quality but slower downloads.

Data rate is effected by the following factors:
Sampling rate: frequency at which the software records the sound data.
Sampling Resolution: number of bits used to represent the signal level of the recording, 8 or 16bit
Mono or stereo: mono suffices for most web applications.
Sound compression: compression results in smaller size files but loss in fidelity.

Sound Quality Sampling
Frequency
Sampling
Resolution
Mono or
Stereo Kilobytes/second
for playback

Telephone 11,025khz 8-bit Mono 11

Radio 22,050khz 8-bit Mono 22

CD-Quality 44,100khz 16-bit Stereo 172

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File Format	Example Uses	Plug-in Support	Helper Ap	Extension	Description
AIFF/AIFC (Macintosh Audio Exchange)	Director Interactive Multimedia Application	Quicktime	Movie Player Quicktime Pro Window Media Player	.aif, .aiff, .aifc	The Audio Interchange File Format (AIFF/AIFC) allows storage of monaural and multichannel sample sounds at various sample rates. Since it is an interchange format, it is easily converted to other fileformats. For these reasons, it is often used in high-end audio recording applications when storage space is not a concern. AIFF alone does not allow for compressed audio data.
WAVE (Microsoft's Windows Waveform)	Powerpoint Presentation	Quicktime	Movie Player Quicktime Pro Windows Media Player	.wav, .wave	A proprietary format most commonly used on Windows-based PCs. This format supports monaural and multichannel samples and a variety of sample rates, just like AIFF.
Real Audio	Streamed Audio on a WebPage	Real Player	Real Player	.RA, .RAM	Real audio used for Streaming media which is useful when dealing with long audio tracks which are very large files.
MIDI	Background Music for a Web Page	Quicktime	Movie Player Quicktime Pro	.midi,.mid	MIDI files store musical notes that can then be playedback by a synthesizer (MIDI instrument or computer's sound card).
Quicktime	Powerpoint Presentation	Quicktime	Movie Player Quicktime Pro	.mov	QuickTime, software that allows you to play and edit various types of media on your computer, includes extremely efficient compressorswhich allow streaming of video, audio and photographic virtual reality.
MP3 (MPEG 2, Layer 3 )	WebPage	Quicktime	Movie Player (More on players)	.mp3	High quality but small file sizes. Quicktime now supports MP3 files.

Sound Quality	Sampling Frequency	Sampling Resolution	Mono or Stereo	Kilobytes/second for playback
Telephone	11,025khz	8-bit	Mono	11
Radio	22,050khz	8-bit	Mono	22
CD-Quality	44,100khz	16-bit	Stereo	172

Contact Information:

Catherine Hays Zabriskie
chays@deans.umd.edu

Janel Brenna-Tillmann
jb434@umail.umd.edu