Operation Manual

Table Of Contents
ADOBE AUDITION 3.0
User Guide
100
p.d.f. (probability distribution function) Controls how the dithered noise is distributed away from the original audio
sample value.
Usually, Triangular p.d.f. is a wise choice because it gives the best trade-off among SNR (Signal-to-Noise ratio),
distortion, and noise modulation. Triangular p.d.f. chooses random numbers that are generally closer to 0 than to
the edges –1 or +1 (that is, the chance of 0 being chosen is twice as great as the chance of 0.5 or –0.5).
Noise Shaping Determines the placement when you move noise to different frequencies. The same amount of
overallnoiseispresent,butyoucanplacelessnoiseatonefrequencyattheexpenseofplacingmorenoiseatanother.
You may also specify that no noise shaping is used.
Different curves result in different types of background noise. The type of curve to use depends on the source audio,
final sample rate, and bit depth. By introducing noise shaping, you may be able to get away with lower dither depths
to reduce the overall background noise level, without introducing a lot of unwanted harmonic noise.
Note: In general, there are no really good noise shaping curves for audio at 32 kHz or lower. With audio at those sampling
frequencies, try the different curves to see if they help, and just choose the one that sounds the best.
See also
“Bit depth” on page 11
p.d.f. SNR loss Modulation
Rectangular 3 dB Yes
Triangular 4.8 dB No
Gaussian 6.0 dB Negligible
Shaped Triangle 4.8 dB No
Shaped Gaussian 6 dB Negligible
Curve Sample rate
Noise Shaping A 44.1 kHz or 48 kHz
Noise Shaping B 44.1 kHz or 48 kHz
Noise Shaping C1 44.1 kHz or 48 kHz
Noise Shaping C2 44.1 kHz or 48 kHz
Noise Shaping C3 44.1 kHz or 48 kHz
Noise Shaping D 44.1 kHz or 48 kHz
Noise Shaping E 44.1 kHz or 48 kHz
Noise Shaping E2 44.1 kHz or 48 kHz
Noise Shaping (44.1KHZ) 44.1 kHz
Noise Shaping (48KHZ) 48 kHz
Noise Shaping (96KHZ) 96 kHz