filter a sound file

Posted on 2009-04-08
Last Modified: 2013-11-25
can anyone help me with the sound file i have to filter it so that i can clear it and hear that word on it. this is has to be done on MATLAB programming software, and i have the file attached bellow for you....
 please not that i have gave the file an extention (.doc), but you have to change it back to (.wav) when you receive it, and when you send it back you have to send it be different extention againg, otherwize it would not be allowed to upload on you website...
anyway, can you please send me the explenation how it flitered please, (if sorted)

thank you
Question by:ferman-k
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Expert Comment

ID: 24099112
No file attached, please upload.

Author Comment

ID: 24102951
i thought i have attached the file, anyway, i am sorry here is the file, but again, please note that i have changed the extention of the file  to .doc   in order to be send, so when you receive it please change the extention back to .wav

Expert Comment

ID: 24106958
Hello, there.  This sounds like a homework assignment, am I right?  If that is the case, we can't do the work for you.  But here's some code to get you started.  You can experiment with various filter types and sizes.  If you don't understand some of the functions, just look them up in the help files.

alo = [1 1 0 0];
ahi = [0 0 1 1];
f = [0 0.05 0.1 1];
n = 50;
h = firpm(n,f,alo);
[x,Fs,Nbits,Opts] = wavread('deng.wav');
y = filter(h,1,x);

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Accepted Solution

masheik earned 500 total points
ID: 24109094
--can anyone help me with the sound file i have to filter it so that i can clear it and hear that word--
read the file using wavread and plot fft of the file  see frequency content and  what should be removed?

you can find examples here

About filtering and reading wav files this link can help you

read and try your own,
an example filter implementation

Expert Comment

ID: 24110081
For the frequency content, try using the pwelch command.  It gives you the power spectral density.  The basic command is


you can also add other inputs to the function for things like sampling frequency and such.


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