In Lesson 5, you implemented two Stingers that should be played regardless of which music is playing underneath. The cymbal swell that occurs when you pass through a teleporter provides a nice musical accent to the score, but it isn’t as important for the player to hear as the musical cue played when there’s a health pickup. This is because the health pickup is usually needed most in the heat of battle and the audible feedback lets the player know they’re in better shape to continue the fight. However, it’s at this same time that players hear a barrage of sounds from the enemy, their own weapons, and the more intense music. All of that sound could bury the health pickup Stinger, so to ensure that it is heard, the volume of the main music should be lowered temporarily.

The approach you’ll use is what’s referred to as a side-chain configuration. This term is associated with classic analog audio systems where the audio signal from one channel is split off and fed to another channel to be used as a source signal that can be used to modify a property of that channel, such as volume. Wwise doesn’t display specific side-chaining features within the user interface, but you can easily build the same result by using a unique feature that allows Wwise’s audio Meters to generate a Game Parameter–RTPC, which can then be mapped to nearly any property of any object, such as the volume of another Audio Bus. This approach offers immense flexibility that goes far beyond the type of control that is offered with conventional side-chaining features found in most DAWs.

Another approach you could use to create a similar result is to use the ducking feature covered in the Wwise-101 course, Lesson 5. The difference is that ducking drops the level of the target bus by a predetermined amount anytime there is any amount of signal detected on the source bus. The actual level of the source bus during the time ducking is engaged is not taken into consideration. Therefore, as the volume of the source bus rises or lowers, the target bus still remains lowered (i.e., ducked) the full amount. The side-chaining approach discussed here provides more flexibility in that it allows changes in the volume of the source bus to impact the target bus dynamically.