Or, you can also try another free memory card recovery tool from http://blog4mark.blogspot.com/2012/12/audio-files-not-v... Honestly, I also have not used it before. But my friend has tried it as his phone memory card is inaccessible. Surprisingly, it has completely retrieved all his photos and contacts back. That’s why I recommend it to you. It is worth trying!
In the future, you should try to keep regular data backups in case of similar recovery problems.