Recording sound from DialUp modem?

Question

Audio

Good evening. Help, please, with advice:
has anyone encountered the task of organizing a recording of a telephone conversation through a modem connected via a parallel line?
- is a software modem from a laptop suitable?
- what programs are only formally suitable for this task, but in fact they do not adequately do what you want from them (it is desirable to register a call from picking up to hanging up)?
- I googled offhand - I read that Voice modems are much better suited for the task, but did not catch the principle from the articles - what does it mean in terms of functionality that the modem is a voice modem?
- how is it better (more realistic) to organize recording - programmatically via a modem, or is it better to look for a modem with support for outputting a signal from a line to a port with a 3.5mm mini-jack, and send a signal to the microphone input of a computer sound card, and write a system Mic-in result?
I would be very grateful if someone shares invaluable experience.

Answer 1

- is a software modem from a laptop suitable?
software modem - this means that there is almost no iron in it. Everything is done by the program (driver). But this does not mean at all that the modem can record sound.
- what programs are only formally suitable for this task, but in fact they do not adequately do what you want from them (it is desirable to register a call from picking up to hanging up)?
not all modems have a built-in pickup sensor. Soft modems do not have it, of course. But even if they have such a sensor, it is very often buggy.
- I googled offhand - I read that Voice modems are much better suited for the task, but did not catch the principle from the articles - what does it mean in terms of functionality that the modem is a voice modem?
if the modem answers OK in the terminal to one of the two commands (AT#CLS=8 or AT+FCLASS=8) — the modem is voice. Otherwise, there may be options, I don’t want to delve into unnecessary details.
- how is it better (more realistic) to organize recording - programmatically via a modem, or is it better to look for a modem with support for outputting a signal from a line to a port with a 3.5mm mini-jack, and send a signal to the microphone input of a computer sound card, and write a system Mic-in result?
through the modem, the sound is worse, a click is heard in the line when the modem “picks up the phone”. Recording through a sound card without a modem (through a 3.5 mm mini-jack) is better in terms of invisibility, but there are difficulties with determining the beginning and end of a conversation, difficulties with determining the number.
There is also a very good option - the IDC 6414 BXL + modem (with a plus) - it can pick up the phone without clicking, loading the line, and has many other goodies. For recording conversations - that's it. Works great with Modem Spy.
Actually, in terms of programs, I recommend Modem Spy for recording from a modem, or Sound Snooper for recording from a sound card.

Answer 2

By the title of the question, I thought that they were looking for the recorded sound of the good old dialing modem.

Answer 3

Faced with such task once. Here's what I can say:
- it all depends on the specific modem and whether it can transmit a voice signal from the line in digital form, and what codecs it supports.
- it may well be that the modem from the laptop does not know how
- I could have ZyXEL, the Venta ZVoice program worked with it, it may well want to work with yours. In any case, download and take a look.
- in a general sense, the task of recording sound is solved as follows: an AT command is given to the modem so that it starts encoding the signal from the league and transmits it. We read this signal in our program, depending on the codec, or save it to a file, or re-encode it to the one we need (for example, mp3).
I struggled for a long time on how to correctly record this signal from the modem, then eventually I gave up and solved the problem by soldering the output and input to the modem, which were inserted into the LineIn and LineOut of the computer, and in the program it only remained after lifting the handset to record the signal from LineIn and play it what you need is just in LineOut.
It may well be that you will find microphones with support for 3.5 jacks. if not, you can do it yourself. I once also thought that it was scary, but after googling, I realized that everything is easy :)

Answer 4

By the way, as an option - on a step-down transformer (120-> 5V) record sound through a sound card. And to monitor the state of the line, use AT commands (however, you will have to poll the modem once every N seconds for the state of the line - if the “hook is up”, start recording, as soon as the “hook is down” - stop recording).
But this, of course, is a terrible bike - it's better to really use a modem and some kind of voice recording utility like vgetty, modemspy, etc.