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

If you think about it in terms of evolution, a nearby predator is much more likely to cause a sudden noise than a sudden light or aroma. So we have a very good reason to wake up at the first one and none for the latter two.