Unreal Engine's audio system provides tools and features to mold the sounds in the game to give them the desired feel. This all starts with your audio source files. Either as mono or stereo files, they can be quickly imported into Unreal Editor and begin breathing more life into your creations. Below are the basic requirements for your audio content and a quick import guide.
Import
The engine currently supports importing uncompressed little endian 16 bit .wav files at any sample rate (although sample rates of 44100 Hz or 22050 Hz are recommended).
| Specifications | PCM, ADPCM, DVI ADPCM |
| Format | .wav |
| Bit Rate | 16 |
| Speaker Channels | Mono, Stereo, 4.0, 5.1, 7.1 |
Importing with the normal sound factory yields a simple sound node .wav that can be referenced by a sound cue for playback. These sounds can be mono or stereo. Importing with a special naming convention gives the potential of multichannel (e.g. 5.1) sounds. Up to 8 channel sounds can be compressed on all platforms, although not all platforms can play them back efficiently. The package saving process does all the necessary work to convert to the platform's native format. There is no strict speaker mapping, so the number of channels infers which channels are played on which speakers (see table below).
| Extension | 4.0 | 5.1 | 7.1 | |
|---|---|---|---|---|
| FrontLeft | _fl | ✓ | ✓ | ✓ |
| FrontRight | _fr | ✓ | ✓ | ✓ |
| FrontCenter | _fc | ✓ | ✓ | |
| LowFrequency | _lf | ✓ | ✓ | |
| SideLeft | _sl | ✓ | ✓ | ✓ |
| SideRight | _sr | ✓ | ✓ | ✓ |
| BackLeft | _bl | ✓ | ||
| BackRight | _br | ✓ |
Compression settings are tweaked to maintain similar quality across platforms. After testing many sounds, our musician determined an XMA quality of 40 was equivalent to an ogg vorbis quality of 0.15.
Single File Import
In the Content Browser:
- From the Content Browser, click the Import button (pictured below).
- Select the
.wavfile you wish to import.
Or
- Select your sound file in a Windows File Explorer window.
- Drag it into the Content Browser in the Unreal Editor.
Multichannel Import
In the Content Browser:
- From the Content Browser, click the Import button (pictured below).
- Select the files that have the appropriate naming convention that will form your sound asset, such as:
Surround_fl.wav,Surround_fr.wav,Surround_sl.wav,Surround_sr.wav. - This will create a four channel asset called "Surround."
Or
- Select all your sound files in a Windows File Explorer window.
- Drag them into the Content Browser in the Unreal Editor.
Exporting a multi channel sound asset will create a mono .wav file for each channel with the above speaker extension naming convention.