Flash Fluorescent Halogen Neon Onion Dim

I can speak without a mouth, I capture waves from north to south, i can entertain you from in your house, i can be loud like a whale or quiet like a mouse.

What has teeth but not a mouth, without a body, nor a snout. It's sharp as a blade, it helps things be made

Arr, beneath the waves where sunlight fades, a metal beast roams the deep. Silent as a ghost, it stalks the sea, unseen but feared by all who sail the briny blue.

What can go up a chimney when down but can't go down a chimney when up?