Just as clarity of focus changes the viewer's perception of your work, so does clarity of sound. The videotape medium offers only visual and auditory canals by which to transmit a message, so take full advantage of both of them. High-quality audio can reinforce the visual image and even make up for lesser-quality images used out of necessity. Poor audio, on the other hand, can undermine your best camera work, and reduce the video's power to less than half of its potential.

Whether you use on-location audio, or post-production sound in the form of voice-overs, music, and other effects, the two bywords are "clean" and "clear." Check the quality and quantity of sound by recording a sample of it and playing it back. In on-location work, this gives you the chance to check your lighting and camera angle at the same time, since they are often hard to judge by the image in a "monochrome 1" viewfinder.

Eliminate as much as possible the undesirable background noises which are present or which might occur. Shut off or move away from the machinery whose internal cooling fans produce humming or whirring noises. Hang a "keep out" or "quiet please" sign on the door to reduce the possibility that someone will walk through the shot or enter the room while telling a bawdy joke. If the size or construction of the room (such as a cavernous space finished in concrete and hard linoleum tile) causes distortions or resonance in on-location narration, try using a lavaliere or hand-held microphone to capture the voice closer to its source. Otherwise, post-production voice-over narration can allow you to record the voice in a more controlled environment.

In post-production, adjust voice-over and background music signal levels so that the music does not overwhelm the narrative voice, washing the speaker and listener away. Music is not a requisite ingredient of a good videotape, however. Cue your narration to take advantage of the power to reinforce the images used in each sequence of the tape. While verbally enumerating the features of your facility, make sure that your narration corresponds to the image simultaneously presented to the viewer. Earlier in this discussion, I recommended five extra seconds of image added onto each slot; they can be very useful at this stage of post-production and editing to pad shots about which you have no more to say than to show.