Why is it so much easier to wake sleeping people by voluntary, but relatively quieter behavior, such as talking or murmuring, compared to louder but involuntary behavior such as sneezing or coughing?

Question

Why is it so much easier to wake sleeping people by voluntary, but relatively quieter behavior, such as talking or murmuring, compared to louder but involuntary behavior such as sneezing or coughing?

In: Biology