---
title: audioFallback
framework: avfoundation
role: symbol
role_heading: Type Property
path: avfoundation/avassettrack/associationtype/audiofallback
---

# audioFallback

The track contains the same content as another track, but in a more widely supported format.

## Declaration

```swift
static let audioFallback: AVAssetTrack.AssociationType
```

## Discussion

Discussion A player that doesn’t support the format of the original track can use the fallback track instead. For example, an asset may contain both stereo and a 5.1-channel audio tracks. In this case, marking the stereo track as the fallback for the 5.1-channel track ensures that devices not capable of playing 5.1-channel audio can still play an equivalent track.

## See Also

### Track association types

- [chapterList](avfoundation/avassettrack/associationtype/chapterlist.md)
- [forcedSubtitlesOnly](avfoundation/avassettrack/associationtype/forcedsubtitlesonly.md)
- [metadataReferent](avfoundation/avassettrack/associationtype/metadatareferent.md)
- [selectionFollower](avfoundation/avassettrack/associationtype/selectionfollower.md)
- [timecode](avfoundation/avassettrack/associationtype/timecode.md)
- [renderMetadataSource](avfoundation/avassettrack/associationtype/rendermetadatasource.md)