The files like that of udhaka shawnthi has been compressed while being uploaded since to meet the server requirement .
1. Click the file to be listened to &save it in your computer.
A.When you click it it is possible that it opens through media player never mind listening to the encrypted voice.
2.Open the saved file through your windows sound recorder.
3.Go to effects menu in the recorder &click "decrease the speed twice" before you hear normal voice.
4.Now play.