Audio Fundamentals

Sound is just quivering air—the faster the quiver, the higher the sound; the more violent the quiver, the louder the sound. Sound pitch, or frequency, is measured in units called hertz (abbreviated as Hz), and a thousand of those units are called a kilohertz (abbreviated as kHz). The best human ears can hear frequencies ranging from a low, throbbing 20 Hz to a squealing 20 kHz. Sound intensity is often measured in decibels, and the range from the softest sound to the loudest in any given recording is called the dynamic range.

Audio data stored on the Mac (or any other computer) usually contains the information needed to re-create both the frequency and the intensity of the sound in any given instance. Most simply, this means ...

Get Macintosh Bible, 8th Edition, The now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.