Filtering noise from sound file

Discussion in 'The Projects Forum' started by flames, Jun 24, 2009.

  1. flames

    Thread Starter New Member

    Jun 24, 2009
    2
    0
    Hi, i am a freshmen in university and would like some help regarding a circuits project.
    I have been given 2 .wav files. One with a clear speech and another with the same speech but with a noise in the background.

    Our project is to isolate the frequency of the noise and design a filter, (low pass, high pass or band pass) using capacitors, resistors and inductors only, to filter out the noise and play the clean speech.

    Software at my disposal is mutlisim as we have not be allowed or trained to use matlab or any other software.
    We can use any software to identify the frequency of the noise.

    Here are the files:
    Speech with noise: http://www.tempfiles.net/download/200906/46197/noisyspeech.html
    Clean speech: http://www.tempfiles.net/download/200906/46198/cleanspeech.html

    I need to create the filter physically (on a breadboard) and on multisim.

    any help would be appreciated
    Thank you
     
  2. bertus

    Administrator

    Apr 5, 2008
    15,638
    2,343
    Hello,

    In the "old days" the phone companies have said that the human voice frequency range is between 300 and 3000 hz.
    To see what frequency the noise is you can use the FFT function of some software.
    I use audacity a freeware program available for windows, mac and linux.

    Greetings,
    Bertus
     
  3. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
  4. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    The speech is buried in noise that has the same frequencies. If you filter out the high frequencies then the important consonants of speech will be filtered out and the speech will be impossible to understand like ducks quacking.
     
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