As planners move forward with crafting a new winter-use plan for Yellowstone National Park, they’ll be gauging public response to the idea of so-called “sound events,” one of the few new ideas in a decade of debate and court challenges over managing winter vehicle traffic in the park. Under two of the potential winter-use alternatives proposed by the Park Service in February, snowmobile and snow coach travel through Yellowstone would be managed by sound events — the total number of noise-producing trips made each day.