Poor quality telephone recordings

[Stevet]

Hello, I own a third party claims adjusting firm and conduct in-person and telephone recorded statements on behalf of insurance companies. If you have ever received a phone call concerning an auto accident you were involved in, it might have been me. I have a need to digitize some recordings of telephone conversations and deliver them via email. My issue is the quality of the recordings is poor. These are recordings that were made on a micro cassette using an inexpensive recorder and a RadioShack mini recorder control that plugs in between the handset and the base of a telephone. I have learned that transferring the tape to the computer via the “line in” verses the “mic” makes a big difference in quality, but it is still not very good. I am guessing that this problem has been dealt with in the past by people much smarter than me. I have spent a fair amount of time playing with different effects in Audacity and have had limited success, I have mostly played with noise removal, high and low pass filters, and equalization. My process has been to import the recording into the computer using windows sound recorder, converting the .wma to an .mp3 file and moving it into Audacity 1.3 beta. After I have done what I can in Audacity I save the file as an .mp3 file with a bit rate of 32kbps, this produces a file size I can deal with and to my ear is no worse that a 128kbps rate recording since it is mono voice. I am not particularly computer savvy so this may not be the most effective way to handle my problem but I am willing to learn. We are in the process of moving to digitally record the statements and that will be the topic of more questions in the near future.
All advice is appreciated.
Steve T

[ignatz]

Have you experimented with Audacity's compression feature on these recordings? I don't know how poor the original micro cassette recordings are, but there is a limit to what Audacity or any other package can do with a recording that is poor to begin with.

Regarding recording phone calls digitally: I used to do quite a bit of this. My recommendation would be to get one of the packages available from Highcriteria.com. Most likely either Total Recorder or Transcription Buddy. If someone will be transcribing the recordings to get them into a Word document or on paper, Transcription Buddy works quite well. Each package costs around $30, but I think have a free trial. You will need a hardware interface to plug in between your phone and your PC. You may be able to buy the interface from High Criteria--I'm not sure. It's a small thing, less than half the size of a pack of cigarettes. You can record in any of several formats which will affect the file size and sound quality. If you are going to email the digital recordings around you may have to use mp3, but if you can put them on an FTP site they can be larger and a WAV file would be suitable. Recording phone calls requires some degree of trial and error, so be prepared to experiment. Cell phones will affect you negatively, so you should hope the party on the other end of the call is using a land line.

[kozikowski]

Some people do this via a Skype account and Pamela Professional or Business software.

Most telephone systems have to struggle with separating the outgoing and incoming voice, outgoing usually being much louder and generally overwhelming. "How can I make the far voice much louder?"

The broadcast call-in show people use special expensive hardware to deal with this. With them, there is no adaptation period. Plug it in and go -- auto nulling, echo cancellation, etc.

Skype calls are already separated for direction and those two Pamela licenses record one direction on Left and the other on Right. It's a snap to process them individually and mix them back together if you need -- or leave them separated. Rumor has it that they deal with Cellphones much better for the same reason, no direction multiplexing, telephone network mismatch, or echos.

Koz

[kozikowski]

One other point. All these techniques work much better when you're not on speakerphone. Either handset or headphones are strongly recommended -- both parties.

Koz