No Doubt singer will reportedly take Xtina's place for season eight.By MTV News Staff Gwen Stefani Photo: Getty Images As much as Christina Aguilera loves her red seat on "The Voice," but it might not be so comfy for an expectant mother. Luckily, she's got another badass diva ready to fill in for her: Gwen Stefani. The No Doubt singer will replace Christina on the upcoming seventh season of NBC's hit reality singing show, according to The Hollywood Reporter.