Decrease missing pick/ban with unique sound
The primary problem with the new ranked matchmaking is that people miss when it's their turn to ban or pick. Many people, including myself, alt+tab during selection phase. A unique sound when you specifically need to take action would help reduce pick/ban misses. Perhaps another warning sound could occur when you have 10 seconds left or something, but I don't think it's necessarily needed.
Experience with the new UI/matchmaking process will cause this to happen less over time. However, this is one very simple enhancement that would help.