Forums

Sound over a phone line using voice modem

Started by Mark January 7, 2004
Hi,

I am trying to play/record sound from my sound card over a phone line
using the modem. So I have a couple of cabels connecting the modem
with the sound card. I have a standard full-duplex voice modem.

I have tried different variations of AT+VLS command, but I can only
receive sound from the line into the sound card (at+vls=5)

I still cannot get the sound from the sound card into the phone
line...

Any ideas?

Thanks
Mark
Mark wrote:

> Hi, > > I am trying to play/record sound from my sound card over a phone line > using the modem. So I have a couple of cabels connecting the modem > with the sound card. I have a standard full-duplex voice modem. > > I have tried different variations of AT+VLS command, but I can only > receive sound from the line into the sound card (at+vls=5) > > I still cannot get the sound from the sound card into the phone > line... > > Any ideas? > > Thanks > Mark
Come again? What are you putting (trying to put) into the modem: analog waveforms, or digits? Do you have a voice modem? How do you couple the cards? Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
Radio Shack has a box that you can take the output of the sound card to the phone.
There might be a lot of hum, so you could buy a line transformer/isolator to get rid of the hum.

Does that help?

"Mark" <mark10@mail.com> wrote in message news:a30790de.0401070944.42c26ea1@posting.google.com...
> Hi, > > I am trying to play/record sound from my sound card over a phone line > using the modem. So I have a couple of cabels connecting the modem > with the sound card. I have a standard full-duplex voice modem. > > I have tried different variations of AT+VLS command, but I can only > receive sound from the line into the sound card (at+vls=5) > > I still cannot get the sound from the sound card into the phone > line... > > Any ideas? > > Thanks > Mark
"Mark" <mark10@mail.com> wrote in message
news:a30790de.0401070944.42c26ea1@posting.google.com...
> Hi, > > I am trying to play/record sound from my sound card over a phone line > using the modem. So I have a couple of cabels connecting the modem > with the sound card. I have a standard full-duplex voice modem. > > I have tried different variations of AT+VLS command, but I can only > receive sound from the line into the sound card (at+vls=5) > > I still cannot get the sound from the sound card into the phone > line... >
Well, I don't have a data sheet for any of those modems so I can only read between the lines regarding what's readily available. vDOT technology appears to be only intended for voice recognition related to voice-controlled dialing. I can imagine a hookup that looks something like this: PC / modem connected to the phone line with vDOT enabled. User takes a phone off hook and utters a command. As long as there's a dial tone, the modem passes the command to the sound card mic input(?)(by a cable one must suppose). The sound card digitizes the voice command. "Software" recognizes the command and translates it into a telephone number by table lookup. The modem puts out the tones onto the Line necessary to dial the number. The connection is made with the user listening to all this. The modem goes to sleep waiting for another off-hook event. .....something like that. So, first, you need to be on the same Line as the modem it seems. Then, there needs to be a dial tone present. What happens after that is all up to "software" isn't it? I guess you've been able to get this far. In concept you end up with a sound file. Now, how to get the sound file to play over a telephone connection? Is that what you have in mind? (Presumably it can go from being a file to a streaming situation after the lower level details are worked out). So, the sound card can generate the analog audio signal and all you have to do is pump that into the telephone line after the dialing has been done. This has nothing to do with vDOT, or any other dialing method, of course. It sounds like it would be pretty simple and somehow I'm thinking that there must be one product or another that's done it. Let's see: - I have a keyboard that integrates a telephone and dialer. No modem involved as I recall. - I have a telephone that integrates with a PC via RS-232. The telephone acts a lot like a modem to the PC where dialing is concerned and the audio stays analog inside the phone. The PC sends ATDT5551111 to the telephone and the phone dials the number and turns on its speaker phone. The PC can also send an ATH to hang up the phone just as if to a modem. It's a really handy gadget for calling contacts that are in a database. Ham radio folks use a device called a "phone patch" that connects the phone audio to their radios - in the olden days they were built with a transformer and not much else. One side to the phone line and the other side to the microphone and headphone jacks. I'm sure you can still buy them and replace the radio with the sound card. The question remains, why would you want to go to the trouble to digitize the voice in the first place? There could be lots of reasons - but you'd like to have a good one - otherwise stay analog. Fred