The adapter is needed to convert the Schuko plug (https://en.wikipedia.org/wiki/Schuko) that the device probably has to a swiss plug.

The AIR 3D is slightly quieter than a conventional hairdryer, but it depends on which hairdryer it is compared to. As a stylist, I work with very powerful hairdryers, which are accordingly louder than conventional household hairdryers. I bought the AIR 3D as an experiment and as an alternative to the expensive Dyson, but I was not so happy with the power of the hairdryer. It is certainly good for home use, as it is handy and light, but I wouldn't recommend it for professional use.