Re: synthesis/analysis: where is the error?

[Fred Herzfeld <herzfeld@xxxxxxxxxxxx>]

Hello Daniel,

I would guess that the problem is in the analysis. The problem is that
if you use a fourier type analysis method the results can be way off
depending on the size of the data that you are using and if you are
using a non-rectangular window. I suggest that you modify the analysis
routine so that the size of the fourier window is an integer function of
the F1 in each case.

Let me know of one particular case.
1. What method are you using for the analysis.
2. What window are you using? Hamming, rectangular, cosine ??
3. What is F1, F2 etc. ?
4. For each freq in (3) give amplitude and phase
5. What is the length of your fourier window in samples ?
6. What is the time difference between samples ?
7. What is the result of your analysis ?

Fred
-------------------------------------------------



Daniel Silva wrote:
> Dear list,
>
>
>
> When I synthesize  a vowel contiuum (varying F1 in steps of, say, 10 Hz) and
> then analyse each sound I always see that there are differences between the
> F1 value specified in the synthesis  and the F1 value obtained in the
> analysis. Furthermore, ther is no linear relation between the two throughout
> the continuum.
>
> Where is the error? synthesis? analysis? bouth? Which is more reliable?
>
> If I want to make a continumm with a fixed step size...
>
> Should I rely either on the values I specify on the synthesis or on the
> observed values of the analysis?
>
>
>
> Thanks!


--
Fred Herzfeld, MIT '54
78 Glynn Marsh Drive #59
Brunswick, Ga.31525
USA