There is an air sound one hears when insulation around an electrical wire is quickly stripped off. It sounds like 'thuup'.
This is the same sound one hears when a soul releases from the 'hermetic seals' of a physical body.
To break the Hermetic Seals, as a metaphor, is to quickly release from physical reality.
Some people hear the thuup accompanied by a tone followed by a golden light, or see an ectoplasmic release emanating from the physical body.