From: norlin@midway.ecn.uoknor.edu (Norman Lin)
Subject: Re: COVOX VS SBPro - Which is Better?
Date: Tue, 29 Dec 1992 19:09:09 GMT
Organization: Engineering Computer Network, University of Oklahoma, Norman, OK, USA

mic@hpfcso.FC.HP.COM (Marc Clarke) writes:

>Questions about the Covox Sound Master:
>1) Can it really do speech recognition?

Yes.

>  a) How hard is it to train the card.

Training is done via a series of several pronunciations of the word in
question.  The number of pronunciations is user selectable, 2 to 9.
This "training" averages all the pronunciations into one "voice template"
which is used for later comparison when a word is spoken into the microphone.

After making a voice template, you can associate it with a "macro",
a sequence of keystrokes fed to the computer whenever the voice
template is recognized as being spoken into the microphone.

The recognition can be done in either hot-key or continuous mode.  In
hot-key mode, the computer only recognizes words when you are depressing
a special hot-key.  In continuous mode, the computer is always "listening"
to the microphone.  Why the distinction?  In continuous mode, the
microphone is prone to pick up background noise, and may incorrectly
interpret it as a word being spoken.  In hot-key mode, the computer only
listens when you press a hot key and are speaking, thus reducing the
chances of error.

I trained it once to recognize "left," "right," "rotate," and "drop" so
that I could play Tetris by voice command.  Kind of fun.

As I recall, up to 64 voice templates may be defined, and 256 macros.

>  b) How often does the card goof?

This question is impossible to answer in general.  If you use
similar sounding words, the performance will drop.  If you use
relatively distinct words, the card does a reasonable job.

Incidentally, it's not the card per se doing the recognition; it's
a software package that uses the card for voice input.  The software
is actually doing the recognition by looking at the input signals
from the microphone through the sound card.

>  c) How much of a hit is it on the system performance when you speak?

System processing stops during voice input.

>  d) How much system CPU do you loose the card trying to interpret background
>     noice as speech commands?

As mentioned above, system processing stops during voice input.  If you
use hot-key recognition, CPU time is lost only when you press the hot key,
which would probably be negligible.  In continuous mode,
you do notice occasional stops and starts of the CPU if you have a lot
of background noise.  The software has a "calibration" feature to account
for ambient background noise.

>2) Can the speech recognition macros drive MS Windows 3.1 menu commands?  Or
>   is the DOS macro set tied strictly to executing key strokes in DOS?   

I don't know about this one.  As I mentioned, I was able to play Tetris
by voice command, so I assume it would work with pretty much any software.

>3) The literature I have seen says that the card records at 22KHZ and plays
>   back at 44KHz.  True?  If so, does that really mean that the 22KHz
>   recording only picks up frequencies to 11KHz (per Nyquist)?

The included software can sample at a rate of 25386 samples/second
(so it says; I've really don't know how to test this).  And since the
22KHz recording "rate" is 25386 "samples/second," yes, I assume that means
that the recording picks up frequencies half of that.

>4) Does the SoundMaster have the ability to speak ASCII strings sent to it?
>   Or is that just a feature of the Covox Speech Thing?

Probably, with the right software.  As with the voice recognition, this
is probably a software and not a hardware feature.  I did not see such
software included with the SoundMaster II, but the SoundMaster II can
completely emulate a Speech Thing.  So, any software that works for the
Speech Thing should work with the SoundMaster II.  In short, if the Speech
Thing can do it, the SoundMaster II probably can, too.

There are also drivers included with the sound card that allow it to
emulate a SoundBlaster.  I can't comment on these, since they require
a 386 processor, and I only have a 286.

Overall, I'm pleased with the card.  The Covox's main selling point
is probably the software that comes with the card (voice recognition,
SB emulation, sample file editor, music composition program).  They
also include a programmer's library for playing back sounds through the
card from within your own programs.  I didn't have much of a look at
these, though.

One last comment (and the Covox documentation says this, too).  The
voice recognition is only suitable for single words, spoken one at a
time.  You can't speak a sentence fluidly and expect the card to
recognize all the component words, etc.  You have to speak each word
separately and slowly.

Norman Lin
norlin@mailhost.ecn.uoknor.edu
Newsgroups: comp.sys.ibm.pc.soundcard