Cutting Through the Noise: Overcoming the Challenges of Location Sound
When faced with capturing clean audio in a noisy environment, don’t be afraid to think creatively and experiment until you find a setup that works for the scene

When working on a tight budget web series, or a low budget film, there is no money — or time — to re-record audio. You have to get it right the first time, in the field. This article will help you overcome noisy obstacles and capture high quality audio on location.

According to Randy Thom, Sound Designer for the film Forrest Gump, essentially none of the sound recorded while film was rolling found its way into the final cut of the movie. Why? The audio quality simply was not good enough.

In Forrest Gump, the actors and actresses returned to a studio to re-read their lines. Dialogue was synchronized using a process called automated dialogue replacement (ADR). Unfortunately, ADR is beyond the capacity of most low budget productions. So what’s the solution? Read on.

One Direction

In almost all recording situations, there are unwanted sounds a filmmaker needs to minimize, or better yet, avoid all together. These situations require a mic adept at rejecting sounds that emanate from certain directions.

This is a job for the trusty unidirectional microphone. This mic is specially designed to ignore sounds that strike it from the sides, while focusing its attention on sounds directed to the front of the mic.

A handheld microphone is one type of a unidirectional mic. It works best when the sound source is very close, like the lips of a singer. Unfortunately, the handheld mic is visible to the audience — in many scripted productions, a mic cannot be seen. Why? If we see a mic while watching an episode of “Modern Family,” it reminds us we are watching TV and ruins the illusion we’re watching a family live out their lives.

A shotgun mic is another type of unidirectional microphone. Unlike the handheld mic, it excels at capturing sound from further away. This type of mic, sometimes called supercardioid or hypercardioid, is extremely directional. It gets its name from the mics heart-shaped directional pickup pattern.

Diagram showing Cardioid and Hypercardioid pickup patterns
The cardioid pick up pattern (left) of a handheld mic is fine when the mic is close, but to get the mic out of the shot, you’ll need a more directional hypercardioid (right) microphone.

A shotgun is the go-to mic for many productions because it can be far enough away from the talent to be out of the camera’s view. It is often used overhead, but can also be used low and pointed up toward the talent’s mouth. Let’s look at three challenging recording situations and explore possible solutions.

#1 Wet Noise

Let’s say you are a documentary filmmaker tasked with interviewing a city mayor about a drinking water shortage — with the backdrop of a roaring waterfall. The waterfall will show the irony of the presence of so much water, but so little that can be consumed.

The first step in this situation is to tightly frame the shot so you can place the shotgun mic as close as possible to the mayor, but out of sight of the audience. You’ll need to position the mayor so the mic can point in a direction avoiding the waterfall in its pickup pattern path. You could try using the shotgun above or below the mayor’s head.

The first step in this situation is to tightly frame the shot so you can place the shotgun mic as close as possible to the mayor, but out of sight of the audience

Another option is a unidirectional handheld mic placed very close to the mayor’s mouth. With this solution, unfortunately, the audience will see the mic. If the film has avoided visible mics so far, the sudden appearance of a mic could be jarring to the viewers.

#2 A Raucous Private Moment

In New York’s Times Square, it’s loud 24/7. Let’s say you are shooting a scene where a couple shares a private moment which includes a marriage proposal. The challenge is to capture the audio of this special moment amongst the sonic chaos of Times Square.

If your audience knows something about the location, they will understand why there is noise in the background. You could start the scene with an establishing shot of Times Square showing the noise sources: taxi horns, conversations of passersby, blaring music and the constant drone of traffic.

A busy city street with people and traffic.
An establishing shot is a good way to give context to unwanted background noise captured in your audio recording. Showing the source of potentially distracting sounds helps the viewer identify and accept them as just part of the scene’s atmosphere.

A shotgun mic will do the trick in capturing dialogue in this situation. Another solution is a mic hidden on the talent, one that is very small. A lavalier mic — the type used by a news anchor — would perfectly fit the requirements. The tiny mic could be easily hidden in a fold of clothing or a scarf.

#3 Sound Fitness

The noise in a sports club or gym presents huge audio challenges. If money’s no object, a filmmaker could rent a gym for a few hours. This solution would offer complete control of noise sources like the whir of treadmills, the banging of weights, assorted grunts, public address music, plus fans and HVAC systems. But what do you do if money is tight?

Let’s imagine you are shooting a scene for a YouTube sitcom amongst the din of the gym. It’s a short scene designed to establish the character as a person who exercises. Maybe the scene could be effective without dialogue. Possibly music and a few different shots of the talent working out would do the trick.

If dialogue simply must be recorded in the gym, a shotgun mic is again a good solution. Starting to see a pattern here? Yes, the shotgun mic saves the day in tough audio recording situations everywhere. It is a must-have tool for all filmmakers who are serious about recording high quality audio on location.

The Sound You Want

When faced with capturing clean audio in a noisy environment, don’t be afraid to think creatively and experiment until you find a setup that works for the scene. No matter which solution you go with in the end, your goal will always be to emphasize the sound you want while minimizing the sound you don’t.

David G. Welton teaches in the Radio/TV/Film Department at Butte College in northern California.

5 COMMENTS

  1. Microphones work best and reject extraneous noise when they’re as close to the subject as possible. A shotgun should be within 12 to 18 inches of your subject, but even closer is better.

  2. In ‘field’ situations, I use a Sennheiser mic. with a pronounced ‘frontal’ characteristic. Until I caught onto the fact and began to use that mic. more intelligently, much of my audio had to be thrown out, due to what was happening ‘behind’ the subject and approximately in-line. I have a handy local lagoon, only a couple of kilometres away and always available, but any recording must be done with the distraction of the noise of the distant city in the background.

    Accepting this situation and trying to clean-up unwanted noise in-post works to only a limited extent, since for each noise removal step, some of the baby goes out with the bathwater. The solution, in my case has been to record suitable audio ‘wild’ during times when the noise problem is at its least acute. A Sunday morning, (with reduced traffic noise), and at a time when it is freezing, or in some other way objectionable so that no-one else wants to be in the vicinity seems to me to be the only answer. Two of the prime wetland areas I work in are on the flight-paths into or out of airports. On one I have to keep a note of landing and take-off times where possible and work around them. Likewise the second instance as well, where the characteristic whine of turbo-prop aircraft is far more objectionable than the roar of jet aircraft.

    But the most important aspect. of all, is to avoid noise sources ‘behind’ your subjects and in-line. Monitoring while recording is a handy way of being aware of noises you would not usually regard as subversive to your efforts, until after returning home.

    • The trick for avoiding sounds behind your subject is to have your shotgun microphone held above your subject, as close to your subject as possible (out of the camera’s sight), and aimed down, about 45 degrees, and directly at your subject’s mouth, so that what is directly “behind and in line” with your subject’s mouth (from the microphone’s point of view) is the ground, which makes no noise. (Croaking frogs are a possibility, I suppose.) In situations where having the microphone high and pointing down is not possible, then hold the microphone low, and aimed up at your subject’s mouth (still 45 degrees). Now it is the sky that is “behind and in line” with the microphone. The ground is often more quiet than the sky, which may have birds and airplanes creating your unwanted noise. If your shot must be wide enough so that you can see the microphone, make sure your camera is mounted on a tripod. Keep the camera rolling after you have finished the shot, pull the microphone out of the shot, and record a minute or so of the same shot without the microphone. In post you can create a garbage matte around the visible microphone, replacing that area with the microphone-free shot.

LEAVE A REPLY

Please enter your comment!
Please enter your name here