Compression formats that exist on all platforms, like PCM, Vorbis and ADPCM, can only be played as "non-original" in the Wwise Transport view when the current platform (top-left drop-down menu) is set to Windows. On most other platforms, bytes are swapped and these formats are therefore unreadable on Windows. However, the audio quality is identical to that which you will get on platforms.
Thus, if you click on "Play" and that nothing is heard, the profiler says "Cannot Play Source" (providing you are capturing), and that the button becomes dark right away, it is very likely that the current platform is not set to Windows. Change it to Windows and it will work.
Of course, this does not apply when the Wwise tool is connected to the game. Playing a sound with the Transport view while being connected actually makes the in-game sound engine play that sound.