You can enable TeamSpeak to display the country flag beside each person's name. To enable this feature do the following:
Go to setting then options at the top of TeamSpeak.
Once in options click Design on the left.
Once in Design over to the right put a check mark beside ?Display Country Flag on Clients?.
Press OK at the bottom.
You should not be able to see the flag of the country the person is from. If you don't know the flag just hover your mouse over the flag and it will tell you the country.