It's all based on filenames and the value that you're telling it to "say". I suggest you read the documentation:
http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/customer_voice_portal/cvp9_0/user/guide/CCVP_BK_S9106620_00_say-it-smart-specifications/CCVP_BK_S9106620_00_say-it-smart-specifications_chapter_00.html
-Jameson
-Jameson