[EvaH (OP)]

Pekka wants to know:

How far away could you hear the sound waves caused by a nuclear bomb? I have read that Tzar bombs cause the sound wave to circle three times around the globe. Does that mean that people on the other side of the world could really hear those sounds waves, maybe with enough detail to distinguish from a normal thunderstorm?

What do you think?

[Halc]

The record for a loud noise was the 200 megaton equivalent Krakatoa explosion, heard clearly 5000 km away, and whose low frequency sound circled the Earth 4 times.

The largest bomb I think is on the order of 50 megatons, so figure from that I guess.  Even small bombs are 'heard' by sound-sensitive devices all over the world, but that differs from humans hearing the sound as it travels through air at human-detectable frequencies.

[Ophiolite]

If you are standing too close you won't hear it at all.

[evan_au]

The key here is "Low Frequency Sound", which represents the initial expansion of the fireball, and collapse once it cools - which is probably in the range 1Hz to 0.1Hz, and is inaudible to the human ear.

There is a network of infrasound detectors worldwide listening for these bursts; their frequency response is 0.02Hz - 4Hz. They can provide an indicative direction and distance to the explosion.
See short video: https://www.ctbto.org/verification-regime/monitoring-technologies-how-they-work/infrasound-monitoring/