I am looking for software the detects and ONLY
triggers on human voice. On AM/SSB comms, a level
squelch is nearly useless.
One implementation, in hardware, can be seen at:
http://www.qsl.net/kc7bum/hf_squelch.html
This is a very usefull device, but I am looking
for a way to do it in software.
-------------------------------
From a thread on the R20000 listeserve:
"
Message 703 of 714
From: W6AFK w6afk@a...
Date: Fri Jan 28, 2005 10:53 am
Subject: Voice detection software?

Lou,

Voice squelches for HF are typically "syllabic squelches". They do not
react on noise but on the pattern of the signal. Simple hardware based
ones
try to detect the presence of voice (low frequency syllabic variations
associated with voice). Although not perfect, these types of squelch
circuits are fairly common on commercial and military HF equipment.

Noise based squelches are practically unusable on HF as they are
triggered
by any random noise... and as we all know, HF-AM/SSB sure isn't FM ;-)

However, I agree that it would be an interesting project if someone
created
a software-based syllabic squelch application that can be used with any
radio... any takers? ;-)

Bruno,
------------------------
So I hope I am making my request clear,
I am looking for software that unlike the
normal VOX is a VOX that only responds to
human voice. My hardwr unit does a great (99%)
job of ingoring non-voice singals. FSK, and some
music, symphonies, fool it.

Terry

Another hardware implementation is in the
ICOM PCR 1000 which has a "voice scan control".
The audio is "opened on a signals that are "modulated"
(from the help file)
Thus avoiding hearing digital signals during search or scan.
I vaguely recall some implementation of this.
So I guess you are looking for a means of detecting whether a signal
is "modulated".

wrote in message
oups.com...
I am looking for software the detects and ONLY
triggers on human voice. On AM/SSB comms, a level
squelch is nearly useless.
One implementation, in hardware, can be seen at:
http://www.qsl.net/kc7bum/hf_squelch.html
This is a very usefull device, but I am looking
for a way to do it in software.
-------------------------------
From a thread on the R20000 listeserve:
"
Message 703 of 714
From: W6AFK w6afk@a...
Date: Fri Jan 28, 2005 10:53 am
Subject: Voice detection software?

Lou,

Voice squelches for HF are typically "syllabic squelches". They do not
react on noise but on the pattern of the signal. Simple hardware based
ones
try to detect the presence of voice (low frequency syllabic variations
associated with voice). Although not perfect, these types of squelch
circuits are fairly common on commercial and military HF equipment.

Noise based squelches are practically unusable on HF as they are
triggered
by any random noise... and as we all know, HF-AM/SSB sure isn't FM ;-)

However, I agree that it would be an interesting project if someone
created
a software-based syllabic squelch application that can be used with any
radio... any takers? ;-)

Bruno,
------------------------
So I hope I am making my request clear,
I am looking for software that unlike the
normal VOX is a VOX that only responds to
human voice. My hardwr unit does a great (99%)
job of ingoring non-voice singals. FSK, and some
music, symphonies, fool it.

Terry

That function seems pretty useful and obvious...I'm surprised it's not
already included in some of the many ham applications out there. Have
you looked through the various ham software yet? Here's a good
starting point: http://ac6v.com/software.htm

I'll toss a couple of ideas out:

- One obvious approach would be to program the DSP on the sound card
to continuously calculate the spectrum of the audio signal, then use a
narrow bandpass filter(s) to look for energy at the appropriate
frequencies indicating human speech. You would need to apply some
further intelligence to the filter output to account for pauses in
speech and fading signals.

- Could voice recognition software be somehow adapted for this use?

---------------

wrote:
I am looking for software the detects and ONLY
triggers on human voice. On AM/SSB comms, a level
squelch is nearly useless.
One implementation, in hardware, can be seen at:
http://www.qsl.net/kc7bum/hf_squelch.html
This is a very usefull device, but I am looking
for a way to do it in software.

I have been searching on and off for several years now.
I suspect that writing the software would be a breeze,
if you are a programmer. My programin efforts make
real programers cringe. Not merely bad, but real
BAD. So bad they can be, are are, used as examples
of how not to do something. I supect Iwill have to live
with hardware units until I can con a friend into writtting
the code.
Looking at the voting gate in the hardware unit, it is clear
that this isn't rocket science. It is however well beyond
my abilities. I have enough projects that I can really complete,
to start on one certain to take a long long time.
While scanning VHF FM voice circuits, a normal level
switch works great. But when monitoring AM or SSB
circuits, a plain level switch just doesn't work. It is a lot
more fun tomonitor a specific freq and only have it pop
out when a real vloice is there.
As a funny note, the digital voice the NWS used to use
would not always trip my VOX squelch. The new voice
works fine. A "speak and spell" will also be treated like
noise and ignored. I boought one for a $1 at a thrift store
just because I wanted to see how TI did it.

Terry

I have played with the PCR1000 and the VSC
works pretty well. Not as fool proof as the
hardware unit I have but pretty decent all
the same.
The only thing is I don't really like the PRC1000.
It suffers from trying to be everything.
A HF and VHF/UHF radio. For some tasks
the PCR1000 is ideal. Keep several lists of hot
frequencies to cover various situations and
call up that set of memories.
I have a chance to trade for a PCR1000 and
an unkown (I don't remember the model number)
Radio Shack "trunking" scanner. I will likely
go for the trade, because you just can't have too
many radios. This PCR1000 has the DSP module
which makes it almsot decent for HF(SW) work.
Terry

You don't like the PCR-1000 but you are going to trade for one? My PCR-1000
does everything fairly well, I am very pleased with it's performance. You
need to use the right antenna or it will overload easily.



wrote in message
oups.com...
I have played with the PCR1000 and the VSC
works pretty well. Not as fool proof as the
hardware unit I have but pretty decent all
the same.
The only thing is I don't really like the PRC1000.
It suffers from trying to be everything.
A HF and VHF/UHF radio. For some tasks
the PCR1000 is ideal. Keep several lists of hot
frequencies to cover various situations and
call up that set of memories.
I have a chance to trade for a PCR1000 and
an unkown (I don't remember the model number)
Radio Shack "trunking" scanner. I will likely
go for the trade, because you just can't have too
many radios. This PCR1000 has the DSP module
which makes it almsot decent for HF(SW) work.
Terry

I am more interested in the Dell PIII laptop that is part of the
trade. A friend bady wants something that I have absolutly
no use for, a piece of test gear that was given to me by a
another friend who was retiring and moving sought, and
even though the PRC1000 is not my favorite radio, it does
have some uses. Mainly like I said. Keep several lists of "hot"
frequencies, covering likely events. Here in Lexington one
for "Winter Snow Emergency", T-Storm/Tornado watch/warning,
nerve gas leak down little south in Richmond. I guess you get
the idea. I have the frequency lists now, it is just a pain to
enter them by hand.
I had pretty fair reception from below AM MW/BCB to above
cell (ATC transpnders) on a lowly 20 year old Tandy diskcone
antenna. The one without the center stinger.
Terry