User guide

Advanced AEC Controls
Click on the open/collapse icon at the bottom of the AEC dialog to reveal the advanced
AEC controls.
Advanced control functionality is as follows:
Non-linear Processing (NLP) Controls
• Enable NLP — this box is selected by default. NLP is
necessary for the removal of echo.
• NLP Presets — click a button to load a set of values
to the three NLP parameters; Max NLP Reduction,
Attack Time, and Release Time.
• Soft
• Normal
• Aggressive
The default parameters (shown at right) match the Normal
preset.
• Max NLP Reduction – the maximum possible reduction in echo artifacts that can
be applied. The range is 0.0 to 80.0dB in 0.1 dB increments.
Default is 50.0dB.
• Attack Time – the speed in which NLP is applied. The range is 0.0 to 100.0msec
in 0.1 msec increments.
Default is 6.0msec.
• Release Time – the speed in which NLP is released. The range is 1.0 to
3000.0msec in 0.1 msec increments.
Default is 150.0msec.
Additional Controls
• Double Talk Echo Reduction – sets the amount of echo reduction applied
during double-talk. The range is 0.0 to 20.0dB in 0.1 dB increments.
Default is 15.0dB.
• Comfort Noise – sets a comfort noise level in dB to eliminate states of complete
silence, which could be perceived as a failed connection. The range is 0.0 to 40.0dB
in 0.1 dB increments.
Default is 0.0dB which turns comfort noise off.
DMP128 • Software Control 43