my External Hard driver HDDE500E03X 500GB is not working

hi everyone

i have been doing backupp for my HD , everyday .. suddenly i got a Problem with my Hard disk , whenever i put it on , it lit and making some kind of moving voice .. showing like its searching , then i can’t see it in my Computer, i have been trying it so that i can get a Backup or recover what is in there am failing , please i would need your assistance my HDD is TOSHIBA