To fully train your speech recognition you need to train it for 1 hour. You can do this at your leisure. I have Dragon Naturally speaking, and Viavoice as well and have found, even though they may say about 15 mins. To get the accuracy you really need an 1 hours training to achive this. 15 mins will work, but not the most accuracy with this at all.
The more training you do the better your speech recogition accuracy.
The more training you do the better your speech recogition accuracy.