[Q]Audio processing technique to increase speech quality?

Hi,

I am in a process to improve the speech quality out of our current
speech codec. Basically, our speech codec is an ADPCM codec with bunch
of interpolation and decimation filters and Sigma-Delta ADDA, and we
have already adjusted all the filters so now it works just fine.
However, we are still not 100% satisfied with the audio quality, we
want to make the sound more clear so we are thinking of using some
audio processing methods (beyond filter coefficients adjustment but
not going to too complex method such like noise reduction ) to achieve
that. I am thinking of using such like Equalizer, Dithering, Echo,
Flager.... to try to make the speech better. So my question is what
are the common ways to achieve that or I am just expecting too much?
Thanks

On Oct 17, 10:51 am, heliboy2...@yahoo.com.tw wrote:
> Hi,
>
> I am in a process to improve the speech quality out of our current
> speech codec. Basically, our speech codec is an ADPCM codec with bunch
> of interpolation and decimation filters and Sigma-Delta ADDA, and we
> have already adjusted all the filters so now it works just fine.
> However, we are still not 100% satisfied with the audio quality, we
> want to make the sound more clear so we are thinking of using some
> audio processing methods (beyond filter coefficients adjustment but
> not going to too complex method such like noise reduction ) to achieve
> that. I am thinking of using such like Equalizer, Dithering, Echo,
> Flager.... to try to make the speech better. So my question is what
> are the common ways to achieve that or I am just expecting too much?
> Thanks

As Johnson points out, may be the answer lies in your architecture. Is
this your own design or an implementation of a standard codec.If
possible can you upload a short wave file from your output and send a
link.