Complex sentence: Beginning in the 2010 season, the models wear microphones so they can be heard when they are talking with Carey or the contestant; and on some episodes only two models are used, with the announcer serving as a third model for games using three models.
Split into simpler sentences: Beginning in the 2010 season, the models wear microphones so they can be heard when they are talking with Carey or the contestant. On some episodes only two models are used, with the announcer serving as a third model for games that feature three models.