Understanding Digital Audio Quality

There are so many variables that can affect the quality of a sound file that I think it's important if we touch on what digital audio files are composed of and how these variables affect a sound file's quality and size. If you are going to be working with audio files that have been digitized and compressed for other multimedia purposes, you need to check their quality and make sure they are suitable for working in Premiere.

A digital audio file's quality or clarity is the result of the sampling rate and bit depth. The higher the sample rate, or the more samples taken per second, the better chance the computer has of reproducing the sound accurately. Re-creating CD-quality sound requires that 44,100 samples or "snapshots" of that sound source be taken for every second that the computer captures the sound. This is represented as 44.1 kHz. If you start working with sound files that were captured at or compressed to a lower sample rate (22.05 or 11.025 kHz), you are talking about working with audio files that will be of lower quality. High-end frequencies are generally dropped when audio is captured at lower sample rates. The lower you drop sample rates, the thinner the audio quality sounds, and you lose that full-bodied feel. Other factors also affect the quality of compressed audio files. For example, bit depth plays a role in the clarity of your file. 16-bit audio files are of much higher quality than 8-bit sound files. Stereo sound files not only affect the sound quality during playback (of files recorded in stereo) but also affect the clip's file size, as much as even doubling the size if two tracks were used, compared to one track with mono.

note

Many books go into further detail about digital audio files. These details are outside the scope of this book.




Premiere 6. 5 Fundamentals
Premiere 6.5 Fundamentals
ISBN: B000H2MVO4
EAN: N/A
Year: 2006
Pages: 219

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