Straighten your back and close your eyes. Come to rest. When you feel ready - start listening to your surroundings. Hear everything around you, all sounds in all directions, all at the same time. Not just one sound but all the sounds.
Nothing is emphasized, nothing is pushed aside.
When the mind is satisfied with experiencing the surroundings it forgets to listen. Do not interfere. Let it wander wherever it wishes, freely. Do not will yourself to experience anything specific. Do not analyze your thoughts, do not be pleased or angry about them.