Sit in a circle
Explain to the group you are going to create a soundscape of an enviroment using just your voices and bodies.
For example, on a beach, a busy street, a restaurant.
Make sure there are differing sounds within the group
Choose a leader to control the sound by varying the volume and pausing certain sounds allowing others to be heard
If you divide the groups up to create a number of soundscapes then each group can try to work out where the soundscapes are.
Have the guessing group sit in the middle with their eyes closed
The leader can conduct the soundscape in a similar way.