Human Voice Digitising By Using A/D & D/A

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Article #14876

#14876

From: Weird!!
Date: Sun, 13 Dec 1992 20:53

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Hi,
   I am trying to build a project which is able to digitise human
   voice by using a microphone input and a small speaker output.
   Since the band width of human voice is no more than 10KHz ( i guess)
   ,therefore I need a antialiasing filter to cut off those unused   
   frequency ( is that right?) What kind of filter is good enough to
   deal with this job? Then the filtered analog voice signal will be 
   digitized by a A/D converter with a sample-hold built-in. My choice
   is National semiconductor DA8020, is it a good choice? 
   Then The 8 bits digital signal will go to a D/A converter( DC8010 )
   Is it a good choice? The analog output will connect with a smoothing
   filter to "smooth" the signal. Finally the message will be played
   back by a 8ohm/4ohm speaker.
   Now, my questions are :
     (1) Are those A/D & D/A  good enough for voice analysis?
     (2) Which antialiasing and smoothing filter is suitable?
     (3) How to interface the microphone with the circuit?
     (4) How to connect the speaker with D/A converter?
     (5) sampling rate = input clock signal ?

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Path: arc1-ca.pugleaf.net!sparky!uunet!think.com!spool.mu.edu!olivea!charnel!helho
From: helho@ecst.csuchico.edu (Weird!!)
Newsgroups: sci.electronics
Subject: Human Voice Digitising By Using A/D & D/A
Message-ID: <1gg7rlINNcs1@charnel.ecst.csuchico.edu>
Date: 13 Dec 92 20:53:09 GMT
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Organization: California State University, Chico
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