I'd like to make a suggestion.
 
1)When export audio with the same file name exists at a storage destination, the file name is changed by making increment numerals to be added to the end of a part except an extension of the file name.
 
2)Automatically to grant the file name.
 
ex)date+time.wav  2015-10-01-10-01+01(02,03,04,05...99).wav
 
I'm sorry by poor English.