The loudest sound ever recorded on Earth was the result of the eruption of the Krakatoa volcano in 1883. The explosion was so powerful that it generated a sound wave that traveled around the world multiple times. The sound was heard as far as approximately 3,000 miles (4,800 kilometers) away from the volcano, and it is estimated to have reached a peak sound pressure level of 180 dB (decibels) at a distance of 100 miles (160 kilometers).
To put this into perspective, 180 dB is extremely loud and far beyond the threshold of pain for human ears. It's important to note that sound intensity decreases with distance, so the recorded sound level was exceptionally high due to its proximity to the source.
It's worth mentioning that in terms of ongoing or regular occurrences, there are natural phenomena that produce loud sounds but are not as intense as the Krakatoa eruption. For example, thunderclaps during severe storms can reach peak levels of approximately 120 to 130 dB, which is still incredibly loud but significantly lower than the sound produced by Krakatoa.