I have seen such systems in use by medical transcription companies. The key is you need to know what you are looking for. If not someone has to actually sit and

I have seen such systems in use by medical transcription companies. The key is you need to know what you are looking for. If not someone has to actually sit and listen to all those hours of recordings. Which translates to a high operational cost. Audio\Speech mining they call it, but it has a ways to go. Even with just one speaker in a noise less environment, there are all kinds of issues with transcription accuracy. I can imagine it being much worse in the kind of conditions the FBI needs it to work in. Ofcourse high end equipment can make things better but it all adds to the cost.