I was having dinner with my wife awhile back at a rustic kind of place in Vermont when a party of about fifteen youths and a couple of adults came in. They were seated at a row of tables and the waitress brought menus.
'Oh great' I thought...'there goes my peace and quiet. these kids will be yelling and throwing food before you know it.' I was convinced they would be loud and obnoxious.
After some time had passed, I realized that the noise level in the place hadn't risen much in decibels. When I looked over at their tables again, they were using sign language. They were all obviously deaf.
So, what is language anyway?

If you smile at me
I will understand
Because that is something
Everybody everywhere does
In the same Language

Crosby, Stills, Nash
(Wooden Ships)