Native Instruments has found some serious issues related to audio in iOS7. TRAKTOR DJ and other audio apps are having performance and stability issues including random disconnections, iOS device restarts, distortion, and chopped audio along with other issues.
Also, Metadata Sync between TRAKTOR DJ and TRAKTOR PRO will no longer function once a device is upgraded to iOS7.
Until these issues are resolved, Native Instruments suggests not upgrading to iOS7. Your device cannot be downgraded to iOS6 once you’ve performed the upgrade.