 Topic: anchor sound (Read 2323 times)
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anchor sound 2015-06-14 14:52:55
hi

I want produce anchor from target sound, how can do it?

The standard anchor is a low-pass filtered version of the original signal with a
cut-off frequency of 3.5 kHz;

thanks

anchor sound If you have fdesign:
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`Fs = 44100;  % Sampling FrequencyN  = 2;     % OrderFc = 3500;  % Cutoff Frequencyh  = fdesign.lowpass('N,F3dB', N, Fc, Fs);Hd = design(h, 'butter');`

Then you can filter(Hd, your_signal).

Otherwise you can calculate a biquad low pass filter like this:
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`w0 = 2*pi*fc/Fs;alpha = sin(w0)/(2*Q);b0 =  (1 - cos(w0))/2;b1 =   1 - cos(w0);b2 =  (1 - cos(w0))/2;a0 =   1 + alpha;a1 =  -2*cos(w0);a2 =   1 - alpha;b = [b0/a0 b1/a0 b2/a0];a = [1 a1/a0 a2/a0];`

You then filter with filter(b, a, your_signal). Q would be 1/sqrt(2) for butterworth.
"I hear it when I see it."

anchor sound thanks for help

in mushra mention anchor made bellow instruction.

. The standard anchor is a low-pass filtered version of the original signal with a
cut-off frequency of 3.5 kHz;
The characteristics of the 3.5 kHz low-pass filter should be as follows:
fc = 3.5 kHz
Maximum pass band ripple = ±0.1 dB
Minimum attenuation at 4 kHz = 25 dB
Minimum attenuation at 4.5 kHz = 50 dB.
how can effect  Minimum attenuation at 4.5 kH z  and Minimum attenuation at 4 kHz  and  Maximum pass band ripple ?

anchor sound Oh, in that case you need to change the filter design quite a bit. Look up the documentation on filter design. You can specify pass- and stopband and attenuation etc.
"I hear it when I see it."

anchor sound ok
I look at f design low pass filter,but I see one stop band in design.
I want use two mininmum attention mention at 4 kHz and 4.5 kHz.
how can this do?

anchor sound 