Operation Manual

ADOBE AUDITION 3.0
User Guide
11
Bit depth
Just as sample rate determines frequency range, bit depth determines dynamic range. When a sound wave is sampled,
each sample is assigned the amplitude value closest to the original wave’s amplitude. Higher bit depth provides more
possible amplitude values, producing greater dynamic range, a lower noise floor, and higher fidelity:
Higher bit depths provide greater dynamic range.
Audio file contents and size
An audio file on your hard drive, such as a WAV file, consists of a small header indicating sample rate and bit depth,
and then a long series of numbers, one for each sample. These files can be very large. For example, at 44,100 samples
per second and 16 bits per sample, a file requires 86 KB per second—about 5 MB per minute. That figure doubles to
10 MB per minute for a stereo CD, which has two channels.
In contrast to a digital audio file, a MIDI file might be as small as 10 KB per minute, so you can store up to 100
minutes of MIDI per megabyte. For more information, see “Understanding MIDI data and VST instruments” on
page 213.
Sample rate Quality level Frequency range
11,025 Hz Poor AM radio (low-end multimedia) 0–5,512 Hz
22,050 Hz Near FM radio (high-end multimedia) 0–11,025 Hz
32,000 Hz Better than FM radio (standard broadcast rate) 0–16,000 Hz
44,100 Hz CD 0–22,050 Hz
48,000 Hz Standard DVD 0–24,000 Hz
96,000 Hz High-end DVD 0–48,000 Hz
Bit depth Quality level Amplitude values Dynamic range
8-bit Telephony 256 48 dB
16-bit CD 65,536 96 dB
24-bit DVD 16,777,216 144 dB
32-bit Best 4,294,967,296 192 dB
192 dB
144 dB
48 dB
0 dB
96 dB
8-bit
16-bit 24-bit 32-bit