Help them to experience this possibly for the first time in their lives. Teach about it (take a look at my blog on silence for some ideas) and then work up from short shared silences - maybe one minute to start with - to longer ones. This will be very precious for them, but also very challenging. Ask them to write or share their experience of these silences, and what silence means in their lives. Mixer
Take them to rich aural environments (start inside the school) and have them pair and log all the sound sources they hear. If you have the resources, let them experiment with multichannel sound. Savouring
Give them a multi-day project to notice sounds and bring their three favourites in to class to share. If you have the resources (eg own a Zoom H2 digital recorder or similar) do this one small group at a time and have them record the sounds to play to all. You could do the same with sounds they dislike. Listening positions
The most powerful of all. Pair them up and have A say what they had for breakfast while B listens from different positions (for example 1 I'm bored; 2 I want to be friends with this person; 3 I'm in a hurry; 4 what can I learn from this - please make up your own also). Have the As share their experiences at the end, then the Bs. Swap and repeat. If they get the principle that you can change reality by listening from a different place, that will be a great gift. RASA (receive, appreciate, summarise, ask)
Practice each element by pairing up again and have listeners turn each element off and on while listening and then both people share their experience. Have them share about their general experience of being listened to at home, in school and elsewhere (especially by adults), and how it affects their own listening to others.