--- a/webaudio/specification.html	Tue Nov 13 16:14:22 2012 -0800
+++ b/webaudio/specification.html	Wed Nov 14 12:16:41 2012 -0800
@@ -3946,7 +3946,10 @@
 positioned in space relative to an <code>AudioListener</code>. An <a
 href="#AudioContext-section"><code>AudioContext</code></a> will contain a
 single <code>AudioListener</code>. Both panners and listeners have a position
-in 3D space using a right-handed cartesian coordinate system. <code>PannerNode</code>
+in 3D space using a right-handed cartesian coordinate system.
+The units used in the coordinate system are not defined, and do not need to be
+because the effects calculated with these coordinates are independent/invariant
+of any particular units such as meters or feet.  <code>PannerNode</code>
 objects (representing the source stream) have an <code>orientation</code>
 vector representing in which direction the sound is projecting. Additionally,
 they have a <code>sound cone</code> representing how directional the sound is.