Terminating app due to uncaught App crashes while using Speech kit ios
The error is telling you that you already have a tap installed on that bus and that you can't have another one.
First you have to remove the tap for that bus. Then again you can install tap on the bus.
let inputNode = audioEngine.inputNode
inputNode.removeTap(onBus: 0)
It will help.
You probably already have a tap on the bus and you can't have another one on that same bus. You should removeTapOnBus when you stop your engine.
audioEngine.inputNode?.removeTap(onBus: 0)
You can try to use it on stop recording
Swift 3:
audioEngine.inputNode?.removeTap(onBus: 0)
It's helped me and should help you too.