< How do you all reduce noise in a recording that has echoes?
The first thing that disappear when reducing noise is the echo of the sounds.
At least it feels like that... :) >
A couple things to note. Firstly, in the 1970s testing showed that the absence
of tape hiss was interpreted by the brain as a lack of ambience. This is
because ambience is displaced in time from the original sound event. Beyond a
certain time threshold, the brain hears the ambience (reverberation) as
uncorrelated to the sound source. Tape hiss, being uncorrelated, i.e. totally
random, is felt to be part of the reverberation, & removing it made recordings
appear to be drier than non-noise reduced recordings. As a result engineers did
their monitoring of the complete encode-record-mix/process-playback-decode
signal chain when adding reverberation.
Secondly, modern, advanced noise reduction algorithms allow the user to steer
the process to effect the desired frequency ranges. The user can aim the NR
process at the most audible noise, leaving the remainder of the spectrum
untouched. Also, a couple passes of 5dB noise reduction tends to be more
transparent than a single pass of 10dB reduction.
Scott Fraser
|