Make a recording of bees and watch him run the other way.
http://news.yahoo.com/s/nm/20071008/od_uk_nm/oukoe_uk_elephants_bees_kenya_1 (http://news.yahoo.com/s/nm/20071008/od_uk_nm/oukoe_uk_elephants_bees_kenya_1)
The only problem I see here is what happens if your standing in front of the elephant when he turns around.
Sincerely,
Brendhan