An HSAXElement to watch. Passing an application's element causes matching notifications to bubble up from anywhere in that application's hierarchy (e.g. AXWindowCreated for any window in the app, not just one); passing a specific descendant element scopes the notification to just that element
An event name, or an array of event names, to watch for with the same listener
A function called with the notification name and the accessibility element it applies to
Register a listener for AX events on a specific element