Luca always jumps off his bed with a loud bang when he wakes…

Luca always jumps off his bed with a loud bang when he wakes up from his nap. Luca then greets his sister with a tickle, making her laugh and cough reflexively. Eventually, his sister begins to laugh and cough when she hears Luca jump off his bed with a loud bang, even before she sees her brother. In this scenario, the loud bang is a(n):