Mindfulness of Sound
Begin by setting a timer for 10 minutes.
If you are in a place with background noise, great. If not, you might want to play instrumental music in the background. I recommend instrumental music because it's easy to get lost in vocals.
Sit with your back straight but not rigid and your chin parallel with the floor, as though there's a string pulling you gently up from the top of your head. this will help with both alertness and attention. You may close your eyes, or if that's not comfortable, you may keep your eyes open and maintain a soft gaze at the floor a couple of feet in front of you.
Notice the points of contact of our body with the chair or cushion, feeling how you are supported by it.
In your own time, turn your attention to the sounds in your environment. There's no need to struggle to hear or identify a particular sound; just imagine opening your ears and allowing the sounds in, experiencing the tone, volume, and movement of each one, being with them as they are and as they change moment to moment.
Each time your mind wanders, gently guide your attention back to the experience of the sounds. Initially, you may need to do this frequently, and at first it might feel as if you're doing it every second or two. With time and practice, this will change.