Annunciations are great for when a traffic conflict arises and you aren't aware of any conflicts.
There are two ways to connect your tablet or phone's audio so you can hear traffic alert annunciations.
Firstly, if you have a bluetooth headset, simply pair your device to the headset.
Secondly, if your audio panel or intercom has a bluetooth or auxiliary input, connect to that either by pairing or using a cable as appropriate. This has the added benefit that all your passengers can hear the annunciations too.
Enable traffic annunciations in the Settings view and try it by tapping the Test button.