Dangerous African mining - GIF

[Saltfever]

I'm fuzzy on this. There's an air compressor running in the background and an air hose running to the hole, but the person jumping in the hole doesn't have a regulator. . ..

I think between 2 and 3 seconds he inserts the bare hose into his mouth. I don't know how he does it but at a very low hose pressure, he probably can inflate his lungs and force exhale at the same time controlling the seal around the hose with his lips. Fighter pilots force-exhale all the time. Force-exhale means you have to push or blow hard against a positive pressure of incoming air.