Voixx was an unknown unknown problem. Cardiovascular safety was tested in the original trial. It passed. Nothing in the data during development suggested it

Voixx was an unknown unknown problem. Cardiovascular safety was tested in the original trial. It passed. Nothing in the data during development suggested it was an issue. But trials can’t detect everything. It wasn’t until it got to market did a safety signal pop up. Then retrospective analyses of large data sets proved it.