I'd use the free
Audacity
for this. Import (cmd-shift-i) the files in the order you want, then go to the Tracks menu, the Align Tracks submenu, and choose the first option, Align End to End. Then simply export your project as whatever file type you want.
Comments
Audacity
I'd use the free Audacity for this. Import (cmd-shift-i) the files in the order you want, then go to the Tracks menu, the Align Tracks submenu, and choose the first option, Align End to End. Then simply export your project as whatever file type you want.
merging files
Amadeus pro is a good app you can join multiple files.