During the initial research and development of the product prototype, multiple experimental tests were performed in-house to help determine the efficacy of the mask in general. Those tests clearly showed how air sprays expelled from different sized containers directly to the mask were continually displaced downwards and away from the face side. Reverse side tests, from the face side out, showed similar effects of highly reducing and dispelling the speed of outbound expelled sprays.
During the products later stage development, Clearly Biotech had third-party simulation studies conducted using expected real-life particulate expulsions between two persons where one expels particulates towards the other person that has a hat-level initiated airstream downwards. In the simulation, the two heads were at one meter (3 feet) between each other and showed that the air barrier was able to almost completely dispel the incoming simulated particulates.
When the study was repeated at the currently CDC recommended physical distancing of 6 feet (two meters), the device produced even better dispelling results.
Clearly Biotech is currently conducting real-life studies of their masks' efficacy and will release results of those studies as they become available.