[Speex-dev] Reg-NC module

[Segher Boessenkool]

> Hello All,
> Does anybody know which spectral characteristics produce metallic 
> sounds

High amplitudes at high frequencies where there aren't
supposed to be any.

> in the output of Noise Cancellation?
> I mean i am looking for the rrot cause of this problem.

One cause of this is clipping; another cause is a
not-quite-steep-enough low-pass filter (so you get
low frequencies mirrored into high frequencies).
Or both of these combined.  Or it could be something
totally different.  You really have to do more
analysis than just saying "metallic sounds" for
anyone to really determine what's happening :-)


Segher