In Wwise there are two different panning rules: Headphones and Speakers. By default, all platforms use the speaker panning rule with the exception of the handheld consoles that use the headphone panning rule. The difference in between the two modes is subtle but helps to provide a realistic and accurate audio experience depending on your listening set-up. This setting can be auditioned in Wwise but also can also be set in the game at run-time.
To audition the two modes:
From the menu bar, click Audio > Stereo Channel Configuration (Speakers)
From the menu bar, click Audio > Stereo Channel Configuration (Headphones)
You can also set the panning rule in the game, please refer to AK::SoundEngine::SetPanningRule in the sound engine documentation.