Creating ambient audio assets

When creating your ambient audio assets, consider:

1. What you want people to use them for, for example to dance to with friends.
2. How your effect will sound on a mobile device - knowing the general range of frequencies mobile devices can reproduce will help determine the levels and types of sound that will perform best.
3. Whether you want the file to loop seamlessly or not. We recommend a small, looping ambient bed. If you choose not to use a seamless looping ambient bed, make sure that your ambient bed runs the max capture length, which for the Facebook camera is 20 seconds.

Creating small, seamless, looping ambient audio assets

If you create a smaller, seamlessly looping ambient sound asset, you'll need to edit the file in a digital audio workstation, such as Pro Tools, and make the edit cut on the zero crossing at the sample level. This edit is essential to creating a seamless loop, so make sure you cut it so that the wavelength at the end of the file and the wavelength at the beginning of the file flow continuously into each other, without a fade applied to either end.

Below are two examples:

1. On the left, the wavelength has been cut correctly and no pop will occur.
2. On the right, the wavelength has been cut incorrectly and this will result in a pop when your ambient bed ends and begins again.

When mixing ambient beds, we recommend that you record audio from a couple of mobile devices and import those files to mix against in your digital audio workstation. An effective ambient bed, much like environmental sounds or a score in a film, should sit well below the production audio (or a person's voice in a capture video), so creating some dummy audio captures will help you achieve the proper levels. You'll be able to make adjustments in AR Studio (only in lowering dB levels, currently), so testing on a mobile device and mixing levels before implementation will save you a lot of time on the implementation stage.

Creating scripted audio assets

With scripted audio assets, consider:

1. The mobile device the person will use to view your effect and environment they will be in.
2. The frequency response.
3. The audio content captured by the microphone on a mobile device.
4. Repetitive tolerance. Audio adds depth, but walks a fine line between effective and destructive. Trigger sounds with caution.

You can use a one shot - a trigger that plays only once all the way through - to trigger a scripted sound.

If you plan to couple ambient beds with scripted effects, make sure to mix both assets together and against the production audio references that you capture from your test mobile device. You'll be able to adjust scripted audio assets in Spark AR Studio just as you can adjust ambient beds, but it's best to get your levels set before importing.