In the Platform Manager dialog box, you can specify volume thresholds and max voice instances for each platform.
The Volume Threshold refers to the point below which a voice will be managed by behaviors defined in the Advanced Settings of the Property Editor. You can specify a default volume threshold in your project in the Platform Manager dialog box. This value will be used if the Volume Threshold is not specifically set using the Wwise API. For more information on managing low level sounds and motion objects and defining the object's behavior when it reaches the volume threshold, refer to Managing Low-Volume Objects.
To define the Volume Thresholds for your project:
Open the Platform Manager dialog box by doing one of the following:
From the Project menu, select Platform Manager.
For each platform, specify the point at which the sound will be managed by the behaviors defined in the Advanced Settings of the Property Editor.
This default value will be used if no Volume Threshold setting is specified using the Wwise API.
Click OK to save your settings and to close the Platform Manager dialog box.
Much like specifying the project's volume thresholds, within a project there is a specified limit of voice instances that can play at one time. If the project exceeds this specified value of voice instances, then it reverts to the Advanced Settings of the playing objects as defined in the Property Editor.
There, Wwise will decide which voices to keep according to which objects have the highest priority. So, those with the lowest priority that are in excess of the the number of virtual voices will be virtualized or killed.