So near, yet so far. You might be able to see the person you want to talk to, but the din of the outside world won’t allow him to hear your voice. That and the fact that what you want to keep your message private makes yelling out of the question. Addressing this first world problem is Fuji Xerox.
After a lot of detailed R&D, they’ve created the Telephoto Megafon which is basically a targeted megaphone of sorts. The 3D-printed gadget will let the user “speak” to someone far away by simply pointing the Megafon towards that person.