Roomtone

The next step to a clean dialog edit is finding room tone for each of the dialog recordings. As mentioned, room tone is the ambient sound of the environment where a recording was made. When a dialog recording is cut up during the picture edit, gaps are often formed between lines (as shown in the screenshot below):

As a result, the ambient noise from that recording pops in and out with the dialog, often to a noticeable degree. Using clean room tone, you can fill those gaps that were created during the edit, creating a consistent bed of noise throughout that piece of dialog:

What makes Room Tone “clean”?

Clean room tone contains the ambient sound of a recording space and nothing else. Cloth rustling, distant car horns, and breaths are common things to avoid in your room tone. For example, if your chosen room tone has a car horn in the background, that horn will be present every time you use that room tone to fill a gap in the edit.

A desirable clip of room tone should be decently long so that it’s easy to work with (depending on your exact uses, anything under 10 frames or so can be problematic). For instance, if you’re filling a three second gap between two dialog bites, looping a 5 frame long bite of room tone can be tedious, and may sound obviously looped to the listener.

There are multiple methods of finding clean room tone. Here we list the most common ways, generally from most desirable to least:

• Room tone recorded by production sound – Sometimes production sound will intentionally record the ambient sound where a dialog recording took place. This is always good to use when available. However, it is worth noting that even minor changes in mic placement can drastically change the sound of room tone. Also, over time, most ambiences will change slightly. It’s always a good idea to do continuous listens to make sure the room tone continues to match a scene.
• Pulling out the handles of dialog bites – Clip handles refer to the extra recording before the start of a clip and after the end of a clip. The picture editor should provide handles for the dialog editor when exporting the OMF/AAF. This allows a dialog editor to pull out the edges of that clip to access the recording around that line.

For instance, say the following clip of dialog was provided in the OMF:

Since the picture editor included clip handles when exporting the OMF, the sound editor can pull out the start of the clip, as shown in the highlighted area below:

The highlighted area appears to be clean room tone! An editor can copy that room tone and paste it wherever it’s needed.

• Splicing together room tone – Oftentimes you won’t be able to find a single stretch of clean room tone throughout the dialog recordings you’re given. In these cases, you may have to take whatever bits of clean room tone you can and “splice” them together into a longer clip of useable room tone.

Other Uses of Room Tone

Room tone is used for more than just filling gaps between dialog bites. Here are someother common uses:

• Fading the background noise of a dialogue recording in/out – If you’re dealing with a particularly “noisy” dialog recording (perhaps it was recorded next to an air conditioner) it can be jarring if that background noise pops in sharply when the dialog starts. To smooth that out, we can use our clean room tone to create a gentle fade in/out of the noise:

• Covering up unwanted breaths/rustles/etc – Sometimes it’s appropriate to cut the natural breaths out of a dialog bite. For instance, if that dialog is serving more as voice over (the speaker isn’t on camera) maybe you want to remove those breaths. Instead of creating harsh cuts out/in to remove the breath, you can replace that breath with clean room tone. This same method can be used for any rustling or other unwanted noises between dialog in the recording.

Using room tone, you should be able to create a full dialog track with no noise popping in and out. Each dialog recording can play in and out naturally by creating fades with that room tone, and ultimately your dialog edits can sound seamless to the listener.