Question: What’s the most loudest sound ?

Sarah Knight answered on 12 Nov 2019:

Thank you for this VERY interesting question! So, first of all, what IS sound? Sound is basically vibrations, which have to travel through some kind of material to reach our ears. The sounds humans hear have almost always travelled through air (although when you hear your own voice some of the sound has also travelled through the bones in your face, which is why your voice sounds different on a recording!). For us to hear a sound, it also has to be within the range of our hearing: we can’t hear sound that are very high or very low.

It’s thought that one of the loudest sounds ever produced was the eruption of Krakatoa (a volcano) back in 1883. Some types of whales produce very loud sounds underwater. And NASA has recorded some very loud sounds from one of its rockets (Saturn V).

Now, there are some VERY big vibrations produced by objects in outer space: black holes, and explosions coming from the Sun, for example. These are still vibrations which travel through some kind of material, so they are in some sense “sound” — but they’re not sound as we know it. The vibrations are often in the form of radio waves or gravitational waves, and travel through things like plasma rather than air. They’re also often far beyond the range of human hearing. But I guess you could think of these as sounds in some sense!