| doggie 2005-12-31, 1:50 am |
| Hi everyone, I’m quite new to DSP and matlab and have some questions here. Hope you guys can help. Any advice would be appreciated.
1) clearSpeech = wavread('clear_car_modified');
clearSpeech = clearSpeech(1:100);
y=fft(clearSpeech);
%soundsc(clearSpeech);
Y=real(ifft(y));
soundsc(Y)
If i take away the real command in the ifft, i will not be able to hear anything in the soundsc(Y). Why is that so?
2) I’m experimenting with weiner or (wiener) filter,
Is it better to formulate the algorithm in the frequency domain or time domain and why?
Using -y(k) = ∑wik x(k-i)
-e(k) = d(k) – y(k)
-wik+1 = wik + 2µe(k)x(k-i)
or
Using H(f) = S(f)^2 / S(f)^2 + N(f)^2
3) weiner filtering requires clean speech. Does that means we have to do spectral subtraction to estimate the clean speech before weiner filtering? If so, wouldn’t weiner filtering be more computational intensive then spectral subtraction?
4) What is the purpose of the overlap add method? Why are we doing it?
Thanks. |