The SD card can be treated the same way that a hard drive is and you can use the same recovery options that you have for a hard drive. By connecting it to your computer by way of a card reader the computer will assign it a drive letter and you can then use any hard drive recovery tool. The problem that you may run into is that if a file hasbeen written over it cannot be recovered.
For example when you delete a file or even formate the drive you are not actualy erasing anything the computer is just allowing the file to be written over and by doing that it then will be lost , you cannot recover a file that has been written over. You can but it is very , very expensive and not worth it.
Both audio and video files can be easily recovered using a commercial Photo Recovery software program. The software tool deeply scans and recover all your lost images, video as well as audio file in few clicks. There are plenty of photo recovery software available. But I suggest you to opt for Stellar.