MULTIMEDIA BASICS: UNDERSTANDING SOUND - Demonstration 1
by Steven G. Estrella, Ph.D.
Demonstration 1 - Digital Audio Sampling Rates and Resolutions
I have prepared five AIFF files of an excerpt from "Doodlin" by Horace Silver and John Hendricks. The files were recorded at different sampling rates and resolutions. The original aiff files were all converted to QuickTime movies for use on the web. The differences in sound quality can be heard by playing the examples below. Changes in sampling resolution from 16 bit to 8 bit produces more noise and degradation in quality than changes in sampling rate from 44 kHz to 22 or 11 kHz.
"Doodlin" - 44 kHz sampling rate, 16-bit sampling resolution, 644 kilobytes
"Doodlin" - 22 kHz sampling rate, 16-bit sampling resolution, 351 kilobytes
"Doodlin" - 11 kHz sampling rate, 16-bit sampling resolution, 176 kilobytes
"Doodlin" - 44 kHz sampling rate, 8-bit sampling resolution, 332 kilobytes
"Doodlin" - 22 kHz sampling rate, 8-bit sampling resolution, 195 kilobytes
The sound quality of the 11 kHz, 16-bit file is the best tradeoff between file size and sound quality. QuickTime movies containing AIFF sound files can be loaded onto any web server and included in web pages by using the appropriate code found in the "HTML Coding" section of the handout as seen below.
<EMBED SRC="doodle16.mov" AUTOPLAY=FALSE WIDTH=150 HEIGHT=24>