NBC plans to capitalize on the success it has enjoyed this season with The Voice by doubling down with a two-hour performance show on Mondays, followed by a results show on Wednesday. It's a template followed by most other reality talent contests. the Voice will segue into America's Got Talent in May, which will introduce Howard Stern as a judge; Stern is replacing Piers Morgan on the panel. Meanwhile, American Idol 's ratings surged Wednesday night as 17.64 million viewers tuned in to the first hour and 19.30 million to the second on Fox. The granddaddy talent contest, which had seen a steady ratings erosion since the beginning of the season, was also up a whopping 12 percent among viewers in the 18-49 age group.