Sound in Wwise will sound the same than in game, when playing with the right platform activated.
For instance, if you set the sound to be encoded in Vorbis on a given platform to a given sample rate, quality factor, etc., playing it back in Wwise will actually do the conversion-decompression to make it sound the same way it would on the platform (So you can have a pretty good idea of how it will sound with the decompression artifacts and the specified sound quality).
Note 1:
Make sure that the option "Original" is disabled in the transport view; otherwise, it will play directly the originally imported wav sound, without the expected effects of compression and decompression.
Note 2:
Vorbis and ADPCM compression formats exist on all platforms, and sound exactly the same on all platforms. However, you may only preview them (as "non-original") in the Wwise tool 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.
