Is this a bug report?

Yes!

Have you read the Contributing Guidelines?

(Write your answer here.)

Environment

Environment:
OS: macOS Sierra 10.12.6
Node: 6.5.0
Yarn: 0.27.5
npm: 4.6.1
Watchman: 4.8.0
Xcode: Xcode 9.0 Build version 9A235
Android Studio: 2.3 AI-162.3934792

Packages: (wanted => installed)
react: 16.0.0-beta.5 => 16.0.0-beta.5
react-native: 0.49.5 => 0.49.5

Steps to Reproduce

1. Install ReactNativeAudioToolkit
2. Empty derived data folder (Preferences->Locations) and Clean Project
3. Run

Expected Behavior

Builds an iOS project on iPhone 8 Simulator

Actual Behavior

Build fails with errors seen in image above.
Redefinition of 'RCTMethodInfo
Typedef redefinition with different types