Check with a sales associate to make sure the microphone you buy is compatible with your recorder. Choosing the wrong microphone could lead to low volume or distorted recordings. Place the microphone as close to the sound source as possible, or use a lavalier microphone. All too often, we receive tapes where the interviewer is perfectly clear, but the person being interviewed cannot be heard because the microphone is too far away. Since the answers are almost always more important than the questions, the recording microphone has to be placed as close as possible to the person being interviewed.
Sound volume is ruled by what's known as an inverse square ratio.
As distance is increased, sound volume is decreased by the square of the distance. An easy way to think of it is for each foot of distance a microphone is away from a sound source, the recorded volume level is decreased by half and the amount of background noise doubles. Because sound volume degrades so quickly over relatively short distances, especially with inexpensive equipment, we cannot stress enough that for good recordings and accurate transcripts, microphones and recorders must be placed as close to a subject as possible and that the recording be done in a quiet setting. Don't be afraid to ask your subject to speak up. All too often we receive low volume tapes where the interview subject is barely speaking above a whisper.