What am I?

Question: My stems firmly planted where I am allotted. My tail is wavy and my face is quite blotted. I relay much emotion though flatly I'm spotted, And grow half my size whenever I'm dotted. I can speak any language yet utter no words. I'm no seed, yet I'm well known among birds. But I do do have a speech impediment. I can say cage but not page, aged but not waged. I can say deaf but not red, bed but not sled. I live on a highway that's structurally sound, Where you might see my friends accidentally bound. It has many lanes, and also long lines. There are lots of sharp turns, and plenty of signs. I am played but not won, made but not spun. The key is to measure before you've begun. What am I?