Name of sound that snake makes?

Snakes hear through their ribs, the part of them that resonates with the ground. This is why it's so easy to trip over a sleeping snake. They don't communicate vocally with other snakes. "Hiss" is a popular conception of a snakey noise. Snakes generally try to make no sound at all since their livelihood depends upon sneaking up on things. This is one cause of other creatures' fear of snakes: you can hear a wolf or a wildcat coming, but a snake is just suddenly, silently there and, very likely, wishing it was a long way away from you, but those unexpectedly sharing space with a snake don't see it that way. Rattlesnakes and their relatives do make noise, but it's a defensive reaction designed to make things too big to eat go away.