Just like putting you ear next to a seashell, a set of headphones can immerse you in another world quite easily through sound alone. The closer you get to the sound source, the further away everything else seems.
The same applies to a microphone. The closer a microphone sits to the sound source you want to record, the less unwanted background noise there would be in the final recording. This is because sound dissipates over distance, where high frequency waves would disappear more quickly than low frequency sounds.
The right tone
Ironically, room tone is silence. This in part would be what we casually call “white noise” in a space – a sound that typifies the general ambiance in a location. These sound waves are absorbed by walls, floor furnishings and the ceiling to create an overall tone in a scene.
Room tones are also called “wild tracks,” which refers to indoor and outdoor sound recording done independently of video. These sounds can be added later in the edit to create background noise – such as ocean waves or urban street sounds. These add ambiance to fill gaps between dialogue.
To ensure what you pick up is exactly what you need, arm yourself with good-quality headphones and a shotgun microphone. A shotgun microphone allows you to point it at different parts of the scene to pick up specific sound bites. Regularly check audio level meters to make sure peak sound levels do not escalate.
Safely and surely
Sound tests and recordings are always recommended to double-check that what you hear is what you’re getting on film. When recording music or a speaker, do a sound test before they begin. Cables or faulty microphones can often pick up electrical noise, crackle or pops.