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Recording Great Sound

In order to record top-notch audio it's important to understand how the human ear perceives sound and how it can enhance the viewing experience.

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Whether you are recording sound as a sound recordist, self-shooting with a DV camera, or helping someone out as a favour, it helps to remember a few basics.

It is very easy to underestimate the importance of good quality audio. It should be appropriate to the visual style, intelligible, undistorted and balanced. The factor that can have an overriding effect on these is the choice of the microphone and its placement.

We hear sound as a combination of the direct and reflected (indirect) sound, a concept known as perspective. In real life we supplement that with visual cues, such as the lips moving or the animation of the body. If we remove the visual cues (the talking person's back to the camera for instance) we must compensate by ensuring there is enough clarity in the sound to make it intelligible.

It is also important to remember that as we get older, we loose the ability to differentiate sounds that are close together in pitch and level. The classic complaint against sound balancers is about the relative levels of speech to background sounds such as effects or music in a variety of broadcast programmes.

Dominate the reflected sound

To make it easier, personal microphones are often used to ensure that the direct sound from the voice dominates the reflected sound. In editing it is an easy matter to loosen the sound to give a natural perspective, but virtually impossible to tighten it. Add to this the convenience of radio microphones and you have a simple workable system for reality TV and documentary recording.

An alternative to this method is to use a directional (gun) microphone. This gives an apparent reduction in the distance between the sound source and the microphone by excluding a portion of the sound that arrives at the microphone from reflecting surfaces at the sides and rear. As long as the microphone is 'aimed' at the sound source accurately, the microphone can be placed as far as two metres away and still capture an acceptable sound. It also produces a sound that matches our own natural ideas of a pleasant sound perspective.

However these microphones are susceptible to low frequency handling and wind noise unless they are used with their correct mounting accessories. They will produce a 'distant' or indistinct sound if not aimed and placed accurately.

Stick to your guns

To many people the choice of microphone is decided for them; it's often what came with the shooting kit. A basic kit consisting of a 'gun' microphone and pole, a few radio personal microphones and a handheld 'stick' microphone, can cope with most occasions that a location shoot needs. However, the microphone that came free on the front of the camera is likely to be the least useful.

It is often too far from the sound source (unless they are standing adjacent to the lens), it picks up the head drum noise from the tape transport and the noise of the camera operators hands (and rings) around the lens barrel. It is useful for atmosphere wildtracks though. After all, some sound is better than no sound.

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This article was written by Steve Jones, an audio specialist in radio and television operations at the BBC.