MLB Umpire Microphones in Action as 2022 Season Nears - Crew Chief Ted Barrett's PA Announcements
Umpire (baseball) - Wikipedia
Instant replay for balls and strikes
MLB Fans Show Appetite for Robo Umps
MLB umpires will have a new view this season -- on Zoom
Two wrongs trying to make a right: Makeup calls are common for MLB umpires, financial analysts and probably you
MLB Lands Deal With Zoom to Help Umpires During Reviews – NBC New York
MLB Umps Are Getting More New Rules Wrong, Says Yanks Coach - InsideHook
MLB partners with Zoom to provide fans a 'more transparent' replay review process
MLB umpires will make replay decision announcements - Chicago Sun-Times
MLB replay review still makes too many mistakes, as the Oakland A's Matt Olson learned again - Athletics Nation
Beyond the grunt: Umpires mic up, and baseball changes a bit