Bit Depth - Adobe AUDITION 1.5 User Manual

A
B
Two sample rates
A. Low sample rate that distorts the original sound wave.
B. High sample rate that perfectly reproduces the original sound wave.
To reproduce a given frequency, the sampling rate must be at least twice that frequency.
For example, if the audio contains audible frequencies as high as 8000 Hz, you need a
sample rate of 16,000 samples per second to represent this audio accurately in digital form.
This calculation comes from the Nyquist Theorem, and the highest frequency that can be
reproduced by a given sample rate is known as the Nyquist Frequency. CDs have a sample
rate of 44,100 samples per second that allows sampling up to 22,050 Hz, which is higher
than the limit of human hearing, 20,000 Hz.

Bit depth

Just as the sample rate determines the frequency resolution, the bit depth determines the
amplitude resolution. A bit is a computer term meaning a single number that can have a
value of either zero or one. A single bit can represent two states, such as on and off. Two
bits together can represent four different states: zero/zero, one/zero, zero/one, or one/one.
Each additional bit doubles the number of states that can be represented, so a third bit can
represent eight states, a fourth 16, and so on.
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