Dog whistle when afraid of dogs with Google Glass

Imagine that you can keep dogs at a distance when you feel uncomfortable around them or when the situation becomes dangerous.
You can choose from a number of frequencies like a dog whistle, to keep dogs away.

It remains to be seen if the high frequencies will bother you seeing as the glasses are so close to your head. Initially Google Glass will be connected to a smartphone or tablet via Bluetooth for internet connection and these devices will be used for other tasks such as the production of these high frequencies.