Audio File basics

DIGITAL AUDIO CONCEPTS
ENCODING		Sound recordings need encoding. Analog electrical signals from a microphone or other source are converted into numbers by a circuit called an analog to digital converter. The analog to digital (A/D) converter uses a technique called digital sampling to convert analog electrical signals into numbers.
SAMPLING RATE		digital sampling is the sonic equivalent of taking a snapshot. By taking thousands of little digital samples per second, an A/D converter can capture an accurate sample by sample representationof the sound. The more number of samples taken per second, the higher the quality. Sampling rate is measured in kilohertz. Most audio CDs are sampled at 44.1kHz. Digital video audio is sampled at 48 kHz.
Bit Depth		Another factor that affects the quality of audio is the resolution of each sample. Similar to images, the better the resolution, the larger the file sizes. Audio CDs have a resolution of 16 bits, as does digital video.
File Formats		AIFF, WAV, MP3 are all audio file formats AIFF and WAV files are recommended for use in Final Cut Pro projects.
	AIFF	Acronym for Audio Interchange File Format; Macintosh audio file format. Can be used for uncompressed and compressed data. See also WAV.
	WAV	The uncompressed Wave audio file format used with Microsoft Windows.
	MP3	An audio file format, especially popular for downloading songs from the web and for storing music in and portable music players. Named for Moving Picture Experts Group (MPEG) 1, Layer 3. Uses lossy compression to significantly reduce file size, but often with little perceptible loss in sound quality. Used to store large song collections on hard disc, download audio to portable audio players, and save multiple hours of music to CD. Some consumer audio players and set-top DVD players can play MP3 audio files stored on CD-R/RW discs.
	WMA	Windows Media Audio (WMA) -- The Microsoft Windows Media native audio file format. Used for compressing, storing, and organizing CDs and downloaded audio in albums on disk. Also used to download audio to portable audio players. Some consumer audio players and set-top DVD players can play WMA audio files stored on CD-R/RW discs.
File conversion		MP3 audio files are severely compressed versions of audio files. Convert all MP3's into AIFFs using ITunes Advanced feature for use in your video/animation projects. 1) In I-Tunes, go to Preferences>Importing>Import using AIFF encoder 2) Select the audio file in I-tunes 3) Advanced menu>Convert selection to AIFF