Ambient Sounds - custom ambients

A description of how to use custom ambient sounds in your map is described in two places.

1. For the Zoned Approach: Ambient_Sounds,_a_zone_approach#Tips_and_Issues, under the heading's "Custom Soundshaders" and "Custom Ambients"

2. Using Ordinary Speakers: Adding_ambient_Sounds_to_your_Map#Custom_Ambients