The answer is maybe, if you jump through a few hoops, but the software does not make the claim that it can do this.
Here’s my more in depth answer explaining the maybe a bit more….
This version of the program is only intended for a single voice. With version 10, you might be able to have some level of success if you setup a profile exclusively for your teacher/professor. You would have to record the lecture, then go through and make corrections in the program to help train dragon to recognize that voice, train it to recognize that voice through your voice recorder, and train it to recognize the voice from what ever distance you are sitting at. (the better the sound the better the transcription, so if you sit in a different location, if people talk a lot or make noise, or if your instructors voice changes (uses a microphone/speaker system one day and not the next) you might run into complications.
All in all this program isn’t intended for this purpose yet, but if you want to get your geek on and see how to make it work, I think there is potential there. Expect to play with it quite a bit, . . . (might be more fun than taking notes and studying ;) )
So this would be one of those situations where if you try to make this tool work in this environment, you may waste some time and money, but if you find a way to be successful, you could save a lot of time!