MLB attempting to remove viral Mets, umpire video from internet
Umpire (baseball) - Wikipedia
Umpires to announce replay reviews to fans
New Wireless Audio Lets MLB Umpires Make All the Calls Very Loud and Clear
MLB to introduce NFL styled umpiring rule, all set to introduce microphones
Mic'd up MLB umpires might announce replay rulings
MLB Umpires Might Get Microphones To Explain Replay Reviews - Bleed Cubbie Blue
MLB news: Umpires to use microphones to announce replay decisions
Umpire (baseball) - Wikipedia