CEDAR Duo – declickle and auto dehiss
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The background to CEDAR Duo auto-dehissing
Perfect restoration of hissy audio is theoretically impossible, but there are many techniques that
CEDAR has developed to reduce the audible effect of hiss with as few side effects as possible.
Our earlier dehissers, such as the DH-1, DH-2, DHX, Dehiss-2 and Dehiss-3 (which were
optimised for reasonably consistent broadband noises such as tape-hiss) were sometimes called
‘auto dehissers’ because they did not require a spectral fingerprint. These were able to achieve
excellent results
if
the user dialled-in the correct values for the noise level, attenuation, and a
third parameter called ‘brightness’ or ‘variance’. However, this method is not what we mean
today when we use the term “auto dehissing”.
In our search for a truly automatic dehisser that you can set up and forget, we have devised an
algorithm that - without human intervention - performs a remarkably good job of identifying the
noise content of any signal presented to it. To use this, you need only set the maximum noise
attenuation that you want, and you will be able to obtain excellent noise reduction without
further adjustment. THIS is the essence of
auto dehiss
.
To make the Duo auto dehiss module as flexible as possible, we have retained a manual mode
that allows you to fine-tune the noise reduction, and full remote control of all parameters so
that you can automate its operation when desired.
