Rattles are an important aspect of the ceremonial and shamanic culture of Northwest Coast First Nations. They are a key source of percussion along with the drum, the voice, and the whistle. They are a story-telling device, used to punctuate or intensify a moment. They can also be a tool, used to calm or invigorate a dancer.
From “Tangible Visions: Northwest Coast Indian Shamanism and its Art”
Wherever a rattle was used, a supernatural presence was thought to be in attendance. The most common form was the round rattle, a globular instrument made of two hollowed pieces of hardwood, usually maple, lashed together, and containing pebbles…Although some round rattles were made for potlatch and secret society ceremonies, the majority were used by shamans. Pg. 239