Audio error recovery for random packet loss

you should read an audio file and simulate random packet loss (with 5%, 10%) then you should use an error concealment (recovery) methods to recover the error as following: 

1. repeat last packet (in the lost packet)
2. add zeros 
3. repeat after frames 
4. average for before and after

comparison (correlation) for the above 4 methods with the original audio file "mat lab" code is needed