In podcasting, the voice is almost always the most important element of the show. Strong, clear voice recordings can not only add credibility and professionalism to your podcast, but make them easier to edit and mix. Understanding when and why to reduce noise will help your podcast to sound it's best!
Most of the time, you want to reduce noise in your recordings. There are certain instances where you purposefully leave some ambiance to create a sense of space (for example, a soundseeing tour with people talking in the background on a crowded street, or screaming fans on a podcast featuring a sports game. However, even here, you don't want the noise to mask what the speaker is saying. For most voice recording, you'll want a crisp, dry sound that can be easily edited and combined with music and other audio.
Tune In, Turn Off, Hit RecordReducing noise in your recordings is easiest done by recording in a quiet place to start with. Make sure to turn off fans, air conditioners, furnaces, and anything else that is making noise in your recording space. If you have your computer in your room with you, try to use a microphone that is designed to reject noise from the rear, and keep the microphone faced away from the computer.
Sometimes, I stuff a pillow or blanket in front of a noisy computer to cut down on the noise from the hard drives and fans (just make sure you're not covering all the vents, and the computer still has good air flow. Some CD and DVD drives can also be noisy if you leave a disc spinning in them, so I always check mine to make sure they are empty before recording.
Some people also buy extension cables and keep the CPU in a closet or different room (make sure it has ventilation), while the monitor, mouse, and keyboard remain on your desk. This can be a bit tricky, though, because you'll usefully want your audio interface with you in the same room for quick microphone level adjustments. Tech-savy podcasters could choose to buy quieter components for their computer, like hard drives, cooling systems, and power supplies and install them.