According to this article in USAToday- it's pronounced "Cone" and not "Kohn"
http://www.usatoday.com/life/movies/2008-09-08-4087110751_x.htm
Great movies!
Franklin Coen's birth name is Franklin Robert Coen.
Joel Coen's birth name is Joel Daniel Coen.
Alison Coen is 5' 9".
Jack Coen was born in 1958.
Noreen Coen was born in 1993.
Kevin Coen was born in 1947.
Kevin Coen died in 1975.
Coen Cuserhof was created in 1908.
Shunter Coen was born in 1902.
Shunter Coen died in 1967.
Eleanor Coen was born in 1916.
Coen Tunnel was created in 1966.