Recording phone calls to PC - from scratch

[TommyC]

I'm new to this forum and to Audacity. I want to record selected phone calls (inbound & outbound) w/ reasonable quality. I have a nice HP workstation (xw4400) w/XP.

As for the hardware, I believe I need some sort of interface to bring the signal in (I have a std. mic input), e.g., Radio Shack's 43-1237:
http://www.radioshack.com/product/index ... Id=2104040

Then I believe I need to install Audacity v1.2.6 to capture the calls to some file type.

Before we leave the topic of Audacity, I have also heard about Oreka for Windows:
http://oreka.sourceforge.net/

Can anyone explain the difference between these 2 utilities (Audacity vs. Oreka)?

Oreka's website says:

Oreka is specifically designed for recording of lots of audio sessions such as telephone calls and easy retrieval through a web interface. Existing software such as Audacity or Ardour focus on different things such as audio edition and studio quality recording, respectively.

I also saw this posted on this forum:
http://forum.audacityteam.org/viewtopic ... 11&t=27667

Finally, I believe I may have to tweak the audio settings in Control Panel | Sounds & Audio Devices. If this is so, any specific tweaks there?

I appreciate your indulgence and any help.

[steve]

Then I believe I need to install Audacity v1.2.6 to capture the calls to some file type.

Install Audacity 1.3.13.
Audacity 1.2. is now very old and is known to have problems on modern computers that will not be fixed because there is no current development on the 1.2.x series. The 1.3 version is a very mature beta and will be the foundation for the new Audacity 2.0 release.

Before we leave the topic of Audacity, I have also heard about Oreka for Windows:
http://oreka.sourceforge.net/

That looks very interesting - I've not seen that before.
It looks like it is primarily designed for capturing streams from VOIP applications, but that's not what you're proposing to do.
If you decide to record using VOIP rather than a land line, then Oreka may well be a suitable application.

Recording both sides of a telephone (land line) conversation is not an easy thing to do without (expensive) specialist hardware. Possibly the easiest way to do it is to use a speaker phone and record with a standard microphone.

[TommyC]

Thanks for your reply, Steve. OK, the beta version (1.3.13) it is.

Yeah, you're kinda right about Oreka and its being aimed toward VOIP. Actually, since I have VOIP/land line, Oreka first caught my eye as a viable solution. I hooked up w/ a knowledgeable guy via the Internet who knows about Oreka and phone recording and I guess it's a bit more complicated. He seems to think the interface could/should be High Criteria's CRD-110 (http://www.highcriteria.com/), which inputs to the sound card. Maybe this device is cleaner/less noise-prone than RS 43-1237 (I mentioned earlier).

Then came his mention of a separate analog telephony adapter (ATA). He said he was pretty sure with cable (VOIP) I can’t see the Internet traffic unless (of course) the cable company had a separate ATA that my phone's connected to. Then (he said) I could "see the packets since this ATA would sit on the network". The ATA would "sniff" the packets.

He later retracted and said that - upon further reflection - he realized that pretty much all cable setups use a single box solution (voice + internet on same box). If I had a separate ATA device (e.g., like Vonage uses), then I’d be able to sniff the packets. But because the voice packets are sent to the cable modem device, these packets cannot be seen by my PC. According to him, I must have a physical device that connects my phone’s handset cord or my phone line to your sound card. Since most homes are cordless phones, generally I’d want an adapter that connects your home phone wire to your sound card. This led to the CD-110 device he mentioned. Maybe this answers you question about VOIP.

Any thoughts on this?

You stated:

Recording both sides of a telephone (land line) conversation is not an easy thing to do without (expensive) specialist hardware. Possibly the easiest way to do it is to use a speaker phone and record with a standard microphone.

This is discouraging. I do not want to use speakers & a mic! The main purpose I have for this is one of documentation: I just need a good record that's discernible. Maybe I can get things set up and see how it goes.

[kozikowski]

Did you say you could not get the Radio Shack coupler to work with your land-line telephone? It should have. It's shortcoming is not that it doesn't work at all, it's that your voice is usually a billion times louder than the far caller, and both voices are in the same sound show, so you can't easily split them.

If you plug that device into your computer's Line-In and set the Windows Control Panels to recognize it, you should be able to get Audacity to record the result.

Windows Control Panel
http://audacityteam.org/wiki/index.php? ... trol_Panel

Koz

[TommyC]

No, I never said I couldn't get the RS coupler to work w/ my land-line phone. Right now, I'm in the planning stages - I'm just trying to understand what's involved software & hardware wise and create a recipe for the task.

What I did ask (and continue to wonder) if the difference between the standard RS devise (e.g., 43-1237) and High Criteria's CRD-110. Is the latter superior/more sophisticated/quieter or are they basically equivalent? Just trying to understand this before I invest.

The other distinction I'm trying to come to grips with is Audacity vs. Oreka in terms of my objectives. (See my earlier post.) If Audacity is the way to go, great.

Koz mentioned:

If you plug that device into your computer's Line-In and set the Windows Control Panels to recognize it, you should be able to get Audacity to record the result.

My PC has a mic input on the front panel, and the standard 3 audio ports on the rear, including:

Analog microphone audio input (mono or stereo).
Analog line level audio output for the main stereo signal (front speakers or headphones).
Analog line level audio input.

I'm not sure what's the difference between the line in and the mic port. Impedance?

The Windows Control Panel link looks very helpful - that'll come in later when I get to the adjustment phase.

Any more comments/thoughts are appreciated.

[steve]

If you're wanting to record from your sound card, for example from the microphone input, then Audacity is a good choice.
For recording voip, then "Total Recorder" (non-free commercial product, but tried and tested solution), or possibly "Oreka" (open source solution, but I know no more about Oreka than you do).

I'm not sure what's the difference between the line in and the mic port. Impedance?

The "mic" input can mean different things on different computers.

Generally on a full size computer, the "line" input is designed for recording relatively high level signals (as you would get form a typical cassette or CD deck) in stereo, whereas the "Mic" input is likely to be a mono input that is designed to record a much smaller (about 1000x smaller) microphone signal and will usually have a 5 v supply on one of the contacts for powering a computer microphone.

On Laptop PCs there is usually only one input, which may be either a "Mic" input, or may be a combined Mic/Line input that can cope with either a mono microphone or a stereo line level input. Whichever type it is it is likely to be fairly poor quality, especially when used with a microphone level signal (often very hissy).

I've not used the device that you mention in your first post, but from what I've read it looks like it should do a reasonable job. It would probably need to be plugged into a microphone input on your computer. The most likely problem that you may have is, as suggested by Koz, that there could be a substantial mismatch between the recorded level of your own voice and the voice at the "other end".

[billw58]

The radio shack devices works, and plugs into the mic port. You talk into the phone, so your voice has "telephone quality". As others have noted there will be a huge difference in level between your voice and the remote voice. You can compensate for this in post-production by applying aggressive compression.

Here's the cheapest commercial solution I could find: http://www.jkaudio.com/inline-patch.htm
Note that in this case you also talk into the phone (not into a separate microphone), so you voice has telephone quality. This devices claims to be able to separate the local and remote voices and send them to your sound card on the left and right channels. Thus it probably connects to the Line Input.

-- Bill

[steve]

As others have noted there will be a huge difference in level between your voice and the remote voice. You can compensate for this in post-production by applying aggressive compression.

There is an alternative method that works rather well provided that both people are not talking at the same time.

If the recording has been made as a stereo track (2 channel mono), use "Split to Mono" (available in Audacity 1.3.x but not 1.2.x)
If the recording has been made as a mono track, then select the track and make a duplicate ("Edit > Duplicate", or Ctrl+D)

Select the upper track and from the Effect menu select "Auto Duck".
The "Threhold" setting should be set so that it is just a little higher than the quiet voice.
The "Duck Amount" needs to be set to the difference in level between the two voices.
Apply the effect, and the loud voice in the lower track will cause the loud voice in the upper track to be reduced.

Delete the lower track, then apply "Amplify" to the upper track.

Note. Any Noise reduction processing should be done before using this technique.

[billw58]

the loud voice in the lower track will cause the loud voice in the upper track to be reduced

Brilliant!

-- Bill

[TommyC]

Thanks to all who posted: Steve, Koz, & Bill. For where I am on the curve, there's a lot to digest here. I think I know enough to be quite dangerous
but it's a good start. I downloaded & installed v1.3.13 and the companion LAME encoder. The user interface is very sophisticated - may have a lot more HP than I need, but I'll give it a try. I need to get an adaptor - I now see that there are many different flavors out there for $25-$30. The link Koz posted on audio settings (Control Panel) for XP will be very useful.

I'll post back when I get further up the curve.