Positioning the microphone correctly is important. It should be to the side of your mouth, not in front, or your breath may interfere with your sound quality. Once you find a placement that works for you, keep the microphone in the same place each time you use it.
Some microphones have batteries. If yours does, make sure you carry extra batteries with you. If your computer’s speech recognition deteriorates, try changing the batteries.
Microphones provided with most software are low quality. If you dictate a lot, consider getting a better microphone. It can make a huge difference. If you improve accuracy one or two percent it may not seem like much, but if you write several pages a day this adds up. It can mean hours in a year.
If there is a change in your sound environment, consider running the “Audio Setup Wizard.” It doesn’t take long. If you have a problem with recognition, check your surroundings. Is there a window behind you that could reflect sound? Try switching to a sound absorbing background such as drapes or a bookcase.
Finally, remember to turn off your microphone when you finish dictating, or pause when dictating for more than a brief moment. If you don’t, you may end up with garbage on your screen as the program puts background noise into words. To turn off the microphone, click the upright microphone icon on your toolbar. You can also use the commands, “Go to Sleep” and “Wake Up,” to turn your microphone off and on. I recommend a microphone with a mute button. You can mute the microphone when you do other things. Note, however, that some mute buttons create static, which causes the program to insert a word you did not dictate. One microphone I use inserted words when I turned the microphone off and on. I sprayed it with Radioshack’s contact and head cleaner—at the on-off switch and at the tail end with the cord pulled out. For a while, this eliminated this problem but eventually it reoccurred, although it was not as bad as it was before. Further sprays with the contact and head cleaner made no difference.
Some microphones have fragile cords which can get damaged and cause electrical interference. I now use a handheld microphone with a sturdy, replaceable cord. With a handheld microphone, make sure you keep it a constant distance from your mouth when you turn your head.
Some of the programs allow you to use a hand-held recorder. They work like a regular recorder but when you want your words transcribed, you hook it up to your computer, select the recording, and click “Transcribe.” These are generally not as accurate as dictating directly to your computer.
Source: PC Speak