To this day, I still think that audio for video is one of the coolest aspects of audio engineering that I’ve had the chance to study and practice. On one side, you have the end product and expectation of reality that watching a scene or movie conveys. On the other, you have a blank canvas and the opportunity to convey something different.
Regarding sound effects, remember that less can be more and that you are not trying to replicate and create every single sound in a scene. Instead, visualize your theme and focal point and stick to it.
It is easy to get lost in a sea of ideas and details. We have all been there, so trust me when I say that checklists are your friend and that the single biggest investment you can make in your project is good planning.
Create a list of your scenes and then break down the elements that make up each scene. Once compiled, you can start working through each of them and iterating through a process of foundation level sounds and detailing.
Projects are made up a blend of sounds that come from sound libraries, foley and field recordings.
The fine art of sound acting and performance has more in common with playing an instrument than just making sounds. Timing is everything because the better you play along with your video, the less editing will be required to make it all fit.
I will go into more detail on making and combining sounds later on. The core of foley lies in having the room and inventory to perform and record in. Full disclosure: you will need an ample supply of stuff, doodads and general bits and pieces with which to produce your sounds.
A handy but hardly exhaustive list of materials worth keeping around for foley sessions:
- Nuts, bolts and screws
- Foil and metal plates
- Ball bearings and wheels
- Glass, bottles and bowls
- Pots and pans
- Metal pipes
- Metal ropes and wires
- Wood planks and sheets
- Hammer(s) – soft mallets and metal tipped
- Mechanical odds and ends, if it squeaks you might want it around
- Pillows and cushions
- Rain stick
- Shoes, lots of shoes
- Surfaces: gravel, wood, stone and slate
In order to get your foley in sync, you should run a video monitor with your video proxy, transport controls and an SMPTE counter so you can time and execute your movements. That is honestly half the fun and where foley gives the feeling of a musical performance in having to play along with so many elements, especially overcoming the need to make mistakes while recording.
Recording and mixing environment
The original iteration of this article talked about using tape, VCRs, camcorders and DAT recorders. Our choice of recording mediums has moved on significantly since then and digital recording has become today’s mainstay.
A shotgun microphone is always my first choice when recording sound effects because of the directionality, balanced frequency response and sensitivity. Shotgun mics work equally well out in the open as they do in the studio. This will be our microphone of choice for the rest of the article.
Camera and auxiliary microphones
The easiest way to record synchronized audio is by using your camera. I strongly recommend attaching an external microphone to your camera and bypassing the camera’s tinny audio.
Staying in sync
Dual system audio is the industry standard for recording audio both on location and in post. It also happens to produce the highest quality results.
The style and target medium will set your frame rate. Film uses 24 fps, European PAL broadcasts use 25 fps, and American NTSC broadcasts use 29.97 fps.
These should be the very first settings you configure when you start your project.
Sample rate and bit depth
Video projects use sample rates of 48KHz as a standard. High Definition video has been the norm for a decade now. This is great news for audio engineers because we now have a great excuse, a pronounced reason, to use higher sample rates.
The next step up is 96KHz. In addition to the higher resolution, this offers a proportional sample rate that easily converts down to 48 KHz. The same logic can be applied to working at 192KHz and sampling down to lower rates for different target outputs like Blu-ray, DVD or television. Without getting into anything too complicated, 24bit will be your default bit depth. Higher sample rates will slightly increase your CPU, memory and storage overhead. Given the specifications on today’s machines, that should hardly be a concern.
Clapboards offer a simple and effective way to create transients that can be synchronized and keep your project organized. You can go one step further by labeling your takes to include take numbers, sound effect name and technical details.
Interpreting the sound you see on screen as plausible is a good indicator that you’re on the right track. A constant theme, especially during Foley, is that you manipulate your sounds and alter your performances to suit the subtleties of the movements you are playing along to. This will make the sound that much more organic and believable. Again, get it right then and there and the work you do in post will be more meaningful and not focused on fixing broken sounds.
- Lapping water in a pan or other vessel
- Water slowly draining from a hose into a vessel can be used to create running water
- Blowing bubbles at different strengths or through different sizes of hose
- Rain sticks, plastic bag and shower heads can all be used to create different styles of rain.
- Waving and flexing pieces of sheet metal. Vary the sound and volume by using sheets of different sizes.
- Softly blowing air at the microphone is basic and can get you by
- Moving a wind-filtered microphone gently in fabric can produce breezy sounds
- Go outside and record some wind
- The slow crumbling of foil or cellophane
- Slowly crushing potato chips
- Blowing into your microphone can emulate the sound of the air that a fire displaces
Them’s fighting sounds
- Striking and hitting couch pillows, try different sizes and densities of pillows for different sound qualities
- The sound of breaking or crunching wood can be used to add extra weight to a particularly nasty hit
- Slap your hand, no pain no gain
- Slap a piece of meat, I’ve found pork belly cuts with skin to produce particularly rewarding sounds; remember to cook the meat after use
- Gunfire in film and games hardly resembles their real-life counterparts; sound effects drastically increase the weight and punch to give the sounds a more dramatic feeling
- Model guns, while lacking originality, can provide source sounds that can be filtered and equalized to produce convincing mechanical sounds like loading and unloading
- Editing, compressing and applying EQ to various pops and bangs can be used as source material and to augment existing sounds when you have to add that extra something
- Animal growls that are slowed, pitched down and run through effects; think tigers and lions (now think back to how many times you have heard a roar in an explosion)
- Striking metal cables, hollow pipes and playing with the doppler effect is a neat way of producing all manner of science fiction sounds
- Filtered white noise and pink noise are good for creating the backdrop rumble or hum of a spaceship
Footsteps warrant their own section because of their importance in creating and maintaining a setting by conveying scale, texture and rhythm.
Keep in mind that we can keep track of about five discrete sources of footsteps. With five or less you will have to provide a distinct yet uniform sound for each person during that scene. Larger numbers need to maintain a proportion in terms of rhythm and quantity and level. 10 people don’t need perfect sync and 10 pairs of feet worth of sound, but they will still need to sound like 10 people and not 100.
Earlier on, I mentioned the need to have a good supply of shoes on hand. During foley try altering the shoes you are recording with, try wearing them on your hands or feet. Mimic the motion of walking and ask yourself the following questions:
- Do the actors walk heavily with their heels?
- What kind of shoes are they wearing?
- What sort of surface are they walking on?
Editing, effects and signal processing
Getting your sounds to fit will require a solid command of editing and processing techniques.
Cuts and fades
When working with lots of different sounds, you need to keep your workspace tidy by keeping your sounds trim. Cut away unneeded parts that can interfere or clutter your soundscape and audio tails that have no place in your scene.
Fades and crossfades are key to getting some sounds to play together, thus smudging or softening a slightly rough overlap.
Try editing at the sample level when dealing with fine anchor point movements or trying to really nail down a sound’s start and finish points.
Reverb and delay
These two effects can be used as stand alone or in pairs to give environments and sounds a sense of size or even wonder. Reverb primarily conveys size or distance, with delay being used to create echos. Don’t forget that a tight delay can be used to create a doubling effect.
Stock sounds need massaging and the most common offender is duration; they are either a bit too long or too short. Time manipulation can be used within reason, but you can’t expect to take a four-second clip and make it last for 11 seconds. The idea is that you can make subtle adjustments of around 10-20 percent to preserve its original qualities and produce a natural-sounding fit.
Time and pitch share a close bond, especially when you go back to tape recording. Slowing a tape down would also shift the pitch downwards. Digital audio allows a lot more control and separation across the two.
Pitching a sound down a few semitones can give a sound the feeling of more power, the opposite applies for pushing the pitch up. A subtle application can be used on dialogue to give the voice a different age quality.
Purchase or make your own?
Sound effects catalogues are great starting points to find and use foundational sounds. The source audio rarely stays in its original form and is there to be nudged into its final shape.
I should point out that there are many royalty-free sound libraries out there that provide plenty of sounds that you can compile and build from.
Sites like Freesound.org have been a staple of mine for years. Also, keep an eye out for discounts and promotions that give away or heavily discount bundles.
I encourage everyone to start building their own sounds; you will do that to a degree anyway with the editing and alterations you apply to pre-fabbed sounds. There are times where you just won’t find the exact sound you’re looking for and the only sensible solution is to go out and make your own. Now get out there and remember to have fun.