There is a great deal of misunderstanding over the function of masks, and the features that exist in different products. The range of different products is extensive, from face-covering to pressure-assisted masks.
Masks are primarily designed to protect the wearer of the mask, although un-valved face-coverings and surgical masks, will remove droplets from the exhaled breath. Any masks with outlet valve features are unlikely to provide any filtration of exhaled breath.
The problem with the un-valved solutions is that they are usually poor fitting, and as much as 20% of inhaled breath can bypass the filtration media, and still meet standard requirements. This is exacerbated by the fact that the media becomes saturated from the exhaled breath, increasing breathing resistance and causing more airflow around the edge of the mask.
Masks with both inlet and outlet valves are much better at maintaining consistent performance but valves and ducts are relatively small, and inconsiderate of the airflow moving through them. They are usually more focused on the mechanical interfaces with the facepiece and filters.
Most masks do not provide any means of ensuring improved communication, so nearly all muffle voices, and make it difficult to understand what the wearer is saying. Misunderstanding when treating patients is a direct concern but having to repeat communication can also be frustrating.
Many masks are disposable, which makes the decontamination process easier. However, simply washing and using their own mask would save a huge amount of waste and allow them to tailor and personalise their own mask for comfort and appearance.