Kernrechtsfrage
Whether the incident qualified as an accident under Art. 4 ATSG, especially the requirement of unusual external impact.
Extrahierter Entscheid
The event did not constitute an accident because the unusualness of the external factor was not proven with the required probability.
Extrahierte Begründung
The court held that unusualness concerns the external factor itself, not its effects. The technical measurements of the device showed no unusually high sound emissions; medical causation alone cannot replace proof of an unusual external impact.