It's not easy. I was so excited when I bought Dragon NaturallySpeaking and the digital voice recorder. I thought I would be able to record while commuting and walking and exercising, then be able to hook up the recorder to the computer and walk away.
Alas, background noise and other factors prevent Dragon NaturallySpeaking from transcribing directly from the digital voice recorder with acceptable accuracy. So it didn't work that smoothly, but I have found a way to make this work.
What I have discovered is that I can be playing the voice file on my speakers, and speaking the text into my headset. In a way this gives me an opportunity to revise the raw speech that I may have uttered on the fly, so the speech that gets transcribed by the computer.
It turns out that when I am commuting or walking, I'm able to talk relatively quickly. Going over the recordings from the last couple of days, I had in excess of 10,000 words. It is perhaps taking me twice as long to get the computer to transcribe the information as it would if the digital voice recorder files would get transcribed directly. But 10,000 words across two days is much faster than I would be able to do if I were merely sitting at the computer typing.
The other thing that is absolutely thrilling is to sit at the computer talking at a regular rate and see the text get transcribed as I'm talking. And that is something I would miss if I were merely plugging in the digital voice recording or walking away.
So I've got my method now. And I am happy.