Newsgroups: comp.speech
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From: pablo@austin.ibm.com (Paul Greenwood)
Subject: Do I need more than 8-bits voice recognition?
Originator: pablo@greenwood.austin.ibm.com
Sender: news@austin.ibm.com (News id)
Message-ID: <CHGqFz.nEM@austin.ibm.com>
Date: Fri, 3 Dec 1993 14:19:10 GMT
Organization: IBM Advanced Workstation Division
Keywords: 8 bits bit 10 12 16 do need
Lines: 31


I am making a voice-input device for a computer.  I am trying to decide if I
need 10,12, or even 16 bits.  If I put the math to it, I come up with:

With 8-bits:
Assuming a 5Vp waveform, 1 / 256 = .00390625
This is .00390625 * 5volts = .01953125 volts of resolution


With 12-bits:
Assuming a 5Vp waveform, 1 / 4096 = .0002441406
This is .002441406 * 5volts = .0012207031 volts of resolution



Now, it seems to me that 2/100th of a volt in relation to 5 volts full-scale
would only be background noise as it is.  This is the 8-bit converter.  12 or
more bits seems overkill.  So, why do the manufacturers of the Soundblaster and
the ThunderBoard have a 16-bit A/D?  Is there a reason?  Am I missing
something?  Is my math right?  Is my assumption that 2/100th of a volt is
insignificant wrong?

By the way, I will be experimenting with Voice-Recognition packages with this
board.  Will that matter?


-- 
            -- Paul Greenwood --  (pablo@netmail.austin.ibm.com)

Injustice anywhere is a threat to justice everywhere.
		-- Martin Luther King, Jr.
