The trailer is the most important promotional tool used in the movie industry. Sometimes, an exciting and action-packed trailer can even be enough to make or break a film, especially if it’s a new franchise that does not feature any especially well-known actors. The music and sound effects used in a trailer can be just as important as the scenes which are shown, so much so that many companies have sprung up in recent years who specialize in creating the perfect audio track for a trailer. 

Sound design for a movie trailer can be a real challenge, even for professionals. You need to grab the viewer’s attention in a very short time, and ideally excite them enough that they will be sure to mark the movie’s release date on their calendar. At the same time, you’ll need to avoid overusing typical trailer sound cliches or being formulaic to the point that your trailer will not stand out from the crowd. If you feel like stepping up to the challenge, then check out our list of the most important trailer audio elements below – and good luck!

Dynamics & Suspense

A common problem for those working with any kind of audio is the tendency for our ears to tell us that louder sounds are always better sounds. The problem is especially prevalent in the pop music industry nowadays, and many songs end up being released with far too much compression and limiting enabled which completely destroys the instrument’s dynamic range.

That last phrase is the key when creating SFX for use in a movie trailer – you should use the entire decibel range to your advantage so that when you do include a loud sound it’s power will not be lost. If you do want to over-emphasize a sound, try bringing it in at a high volume before fading it out slowly over so much time that the viewer is unlikely to notice. Suddenly, you have a lot more dynamic range available for the next “big event”. 

Consider a scene in a server room where all the computers are switched on with their fans running. These fans slowly get quieter as dialogue takes over the scene – in the next moment, there is a powerful explosion which completely fills the soundstage, made even more powerful by the increased dynamic range created by slowly tapering off the volume of the background sounds.

Contrast

Have you ever noticed that trailers almost always feature at least one short section of complete silence? This isn’t just a coincidence, as silence can be every bit as powerful as an explosion when used in the right way. It is sometimes suggested that this effect is the result of our evolution – sounds will always stand out more if they follow complete silence, whilst an abrupt cessation of all sound such as something stopping moving is also sure to grab our attention. You should use this to your advantage to create contrast in your trailer soundtrack.

Whilst contrast can work well to divide different scenes in a trailer, sometimes you will want to create a smooth transition as well. This can be achieved by using riser or swell sound effects to build towards an event, whilst booms, cymbal crashes, and swooshes will often sound great directly after an event takes place. 

You can combine both techniques by inserting a small pause at the end of a riser sound effect – perhaps half a second of silence – before dropping straight onto a huge boom-type sound effect a moment later. Your audience is sure to notice that sudden lack of sound for a moment, so whatever happens in the next scene is guaranteed to be overemphasized. 

Automation

Professional sound-editing software such as Cubase, Nuendo, Audition, or Sound Forge, all have many effect automation tools built into them to assist with repetitive or complex tasks. You can also use automation to create multiple variations of the same effect in creative ways, perhaps by layering many sounds together and then changing the volume of each layer on the fly.

You can use automation to control the parameters of any industry standard VST plugin, and even map those controls onto knobs or sliders on a MIDI controller to give you some physical control over the outcome. When you hit record on your sequencer any movements performed on your MIDI controller will be recorded onto the editor and can be played back later alongside the audio track. 

The ability to duplicate sections of automation can be a godsend if you have many repetitive sections to produce as part of your trailer sound design. When you are happy with the results, be sure to mix down the new sound complete with automation onto a new track. This not only saves on CPU resources, but also means that you can potentially use the automated sound as a sample in future projects.