how to filter noise?

Question

abc 2012-12-17

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/56758-how-to-filter-noise

回答： NORZALINA AKHARUDDIN 2020-12-30

How to play the sound to compare the filter sound..?? tq

[y,Fs,bits] = wavread('voice.wav');
Nsamps = length(y);
t = (1/Fs)*(1:Nsamps);          %Prepare time data for plot
%Do Fourier Transform
y_fft = abs(fft(y));            %Retain Magnitude
y_fft = y_fft(1:Nsamps/2);      %Discard Half of Points
f = Fs*(0:Nsamps/2-1)/Nsamps;   %Prepare freq data for plot\][p
%Plot Sound File in Time Domain
figure
plot(t, y)
xlabel('Time (s)')
ylabel('Amplitude')
title('Tuning Fork A4 in Time Domain')
%Plot Sound File in Frequency Domain
figure
plot(f, y_fft)
xlim([0 1000])
ylim([0 1800])
xlabel('Frequency (Hz)')
ylabel('Amplitude')
title('Frequency Response of voice')
Fs = 44100;  % Sampling Frequency
N    = 1000;     % Order
Fc1  = 800;      % First Cutoff Frequency
Fc2  = 1000;      % Second Cutoff Frequency
flag = 'scale';  % Sampling Flag
% Create the window vector for the design algorithm.
win = hamming(N+1);
% Calculate the coefficients using the FIR1 function.
b  = fir1(N, [Fc1 Fc2]/(Fs/2), 'stop', win, flag);%
newy=conv(y,b);
wavwrite(newy,Fs,bits,'your-group-number');