I had a black circle with white text symbol in the middle. It would show up on every screen and wouldn't go away. I went to applications clicked on the Talk Back app, force stopped it, then uninstslled it and waaa la, it went away. I had called Google, LG, emailed the developer and everything. I went to Android ventral and asked it how to remove the Talk to speech icon, it took me to a forum with questions and others had found the answer, hope this helps everyone.it was so frustrating and annoying. Good luck.