"Dual audio" means that a device or content has the capability to produce or switch between two different audio tracks, usually in different languages. Full definition
Let's cross our fingers for dual audio options to be included in the game. (goombastomp.com)
The devices are said to offer a premium audio experience to consumers, and the aforementioned dual audio Bluetooth support will likely only help them impress you in the audio department even further. (androidheadlines.com)
The game offers dual audio, as well as the ability to choose an audio option for each individual character. (arcsystemworks.com)