ELI5 Why would most of us awaken to a sudden noise but perhaps less so to a sudden light or aroma?

Question

So, we have 5 basic senses. When we’re asleep, I wondered why a loud noise would likely rouse us whilst a sudden bright light may rouse less of us and even less would probably wake up to a sudden odour.

In: Biology

Answer 1

You can hear a knock on the door when someone visits your house, but you can’t smell them. Also, eyelids.