Reading: Room tone

Following on from issues with atmos sounds in my Assignment 3 moving image, I found an article on room tone by sound designer Woody Woodhall.

‘Room tone, sometimes called room noise or fill, is simply the recorded sound of a particular room that a scene is being shot in. That sound is caused by many factors – lights, refrigerators, air conditioning, people, furniture, as well as the “sound” of the microphone, the “sound” imparted by the recording device and the specifications of the recording’ (Woodhall, 2018).

No two rooms have the same room tone.

The main function of room tone is to cover unwanted noise and fill gaps in the sound.

A dialogue editor can fix problems with sound by adding a bit of room tone over the offending noises and adding a precise edit and some cross-fades.

If room tone has not been recorded, you have to create it from the audio clips you have:

  • take parts of the scene that are quiet
  • you can also find it in the handles of the audio clips – the longer the handles the better
  • put it all together and apply some noise reduction software to get rid of some of the issues
  • then double the length of your tone by copying it and reversing the second half

When editing location audio, besides creating a seamless dialogue track, the dialogue editor also creates a track that is called production effects (PFX) – any useful location recording that does not have dialogue in it (e.g. breaking a glass, knocking on a door, working in the kitchen, running water, chopping vegetables, etc.).

Editing the location PFX onto non-dialogue tracks helps create the final sound effects stems and sub-mixes.

Room tone is needed when PFX are removed or when bad lines are muted and replaced by ADR.

Room tone is also needed when you get busy noise in the middle of what should be silence. You can cut out the noise and replace it with room tone, if it matches.

Room tone can be used to keep the dialogue track filled with audio from start to finish, while other sounds might be happening in the sound track.

Room tone can be useful in allowing sound effects editors to enhance the PFX in the sound design and help blend foley recordings with the PFX and with the dialogue tracks for the final mixing.

‘Room tone is the glue in the sound editing that creates the continuity from edit to edit.’

Every room sounds differently according to its shape and contents, what machines are running, what traffic is passing outside, even what natural sounds can be heard such as birds. These things change throughout the day, so getting room tone at different times of the day can be useful.

Even one shot can have completely different tone than another shot in the same room, depending on what direction the mic is facing.

On-set room tone recordings are important because creating usable room tone from scraps of location recordings is difficult.

The most essential room tone to record is that in odd places.

Movies that are quiet or that have sparse music score and minimal sound effects leaves the dialogue track bare and audiences will be aware of this.

Room tone is an inevitable part of the filmmaking process.

30 seconds spent recording room tone on location can save dialogue editors hours in post production trying to create it.


Woodhall, W. (2018) ‘Room Tone – 28 Weeks of Post Audio Redux: #2 Do we really need it?’ On, July 02, 2018. At [Accessed on 10 November 2018]

Reading: Seeing with your ears – Spielberg and sound design

There are three ways you can build up tension in a scene – camerawork, pace, music.

Films have two ways into your brain: eyes and ears. When you are watching a film, these two senses are interconnected.

The visual side of the film gets the most attention because it is in front of you. But the visuals are in many ways the ‘face of the operation’. The sound ‘is actually the puppet master, the one that really holds the power.’

Sound affects what you see and from what perspective you see it.

As soon as the audio starts, you should be placed within a perspective. The sound design picks specific sounds out to tell the story within the scene.

In film, you see with your ears. The power of sound design is its invisibility behind the image. If dialogue sounds close, then the viewer is close to the person that is speaking, wherever they are.


Example: Munich (2005) dir. Stephen Spielberg

The Assassins arrive outside an apartment building to detonate a hidden bomb.

The 4′ 50″ scene is without music and almost entirely without dialogue. How is the tension built within the scene?

By building a bed of constant, noisy, city ambiance, and singling out and stringing together like beads on a wire, key noises that the tell the story.

The background that Eric Bannagh and his team are going to assassinate a man in his home by getting him to answer a phone they have secretly installed a bomb in.

The string of isolated plot sounds

  • the car with the assassins arrives
  • the dialogue of the targets wife and young daughter, and their car going away
  • the coins and rotary phone that make the call
  • the priming of the detonator
  • the truck passing by

The first moment of trouble in the scene comes in sound. Up until this point in the scene, isolated noises represent the steps of the plan going smoothly. The truck passing by represents a break in that chain and a hitch in the plan. At this point the ambience outside starts to take on some strange qualities. There’s a high pitched whine, like a train stopping, on top of everything. Just like the moving truck blocks the assassins view, the movers talking keeps them from hearing the daughter’s car returning back to the apartment. We hear her footsteps, not her voice this time, which continue indoors. In the apartment the ambience is quiet. The incredible thing about this scene is that Spielberg builds the tension, not by working towards a great crescendo of noise, but by gradually subtracting elements. While the daughter is in the apartment, the danger is signalled by a single sound effect, the rotary dial of the telephone. The climax to the scene is silence. It’s a silence that works so well because it anticipates the noise of an explosion to come. At this point, the ambience has become really impressionistic. When it comes back in, it has echo that reverbs the hurried footsteps and an anxious siren. The whole sound universe corresponds in a way to the assassins, to their feelings and their nerves.

This scene is made with no dialogue, no music, just camera work and sound design.


Key points for me

When making a film always ask myself ‘what do my ears see?’ Because sound affects what the viewer sees and the perception from which they see it, I should build scenes using camera work and pace, and a sound design that carefully picks out key sounds to tell the story.


Nerdwriter (2018) Aeon At: (Accessed on 14 October 2018)