Sit outside for about an hour. Write down the sounds you hear.

When I'm out on a run and I hit North Bank Park on the Scioto Mile, I like to pause my music and just take a seat on the stairs or lay in the grass for a bit. 

I can hear:

The mama geese corralling their babies and fending off humans
A bicyclist racing down with his little speaker blaring Sam Smith
The distant roar of a train
The clamour of construction crews chit chatting and drilling
Three older women power walking on their lunch break
The faint buzz of a fly
Cars honking at each other on the street behind me
The wind rustling the dead leaves nearby
The low hum of the river passing
Little kids laughing at a picnic
Pounding footsteps of a runner
A door slamming shut.