She never recovered after a contestant called her on using auto tune on X Factor
Link: https://www.youtube.com/watch?v=Dz5xJAZpsXE
Completely destroyed, she totally went off the rails after that.
Autotune should be banned. The technology was invented to correct a singer's voice if the person hit a couple of notes off-key. It saved having to redo the entire recording. It was never intended as a crutch to cover up lack of talent.
The sad thing is, this effect has invaded all genres of music. I even once heard a reggae song done with autotune, believe it or not. Anytime a song containing this garbage comes on I change the station.
True artists don't use autotune.