If I remember correctly, babies learn to distinguish vowels from consonants from near birth when adults speak to them in that annoying high pitched "coochy coochy coo" dialect. After 6-12 months of life this starts to hold them back as they need to transition to hearing normal sounds and seeing the people mouthing them. The puppets with hinge-flap mouths, exaggerated and insanely high pitched accents in Sesame Street are ridiculous. I would strongly discourage letting your little ones watch this show.

Also Sesame Street is very New York. The rest of the world doesn't live like this. I recommend local kids TV shows with real humons performing. Some short cartoons are fun, many of them are terrible, but the sum total of TV is dose dependent. Turning it off straight after their favorite show might result in a little argument but you'll be pleasantly surprised when 5 minutes later you catch them doing something (anything) else. Usually something creative, social, and developing fine motor skills, if not simply running around outside. And subsequently you'll find them turning it off themselves.