The number of concurrent physical voices (that is, sounds that actually play) has a major impact on CPU usage. To reduce the amount of CPU resources that voices use, you can use the following settings to reduce the number of concurrent voices:
Playback limits determine the maximum number of instances of a sound that can play at the same time.
Priority determines which sounds to kill or send to virtual voice behavior in the event that the playback limit is exceeded.
Virtual voices are sounds that occur during runtime but do not actually play if they fall below a defined volume threshold or exceed the defined playback limits. The recommended virtual voice behavior is "Kill if finite else virtual". Refer to Advanced Settings Tab: Actor-Mixer Objects.
For more information, refer to Managing Priority.