harmonic noise shaping filter

Started by ashwin_c29 August 2, 2008
Hi All,

I was wondering as to how the harmonic noise shaping filter improves
the performance of the G.723.1 codec. Does it like improve the pitch
harmonic structure as well and if so are the improvements restricted
to a specific set of pitch harmonics? Moreover why does this filter
have a transfer function which is the inverse of the long term
prediction filter? I would be really grateful if someone could answer
these questions of mine.