This won't eliminate the noise, but if your tenants don't have anything down it can help soften some of the impact noise.As another poster mentioned, try to avoid putting tenants with kids in upstairs units.

All that said, investors will jump in droves when prices soften.

I am from Alaska and we are highly dependent on the oil prices which are down, so I foresee at least some sort of softening in the real estate market. 

That may soften the blow. 

The sidewalk to the front door looks a bit rough and I think Nikolas was right to suggest softening and widening it - plants are one option - just a row of bricks along each side could be another.  

Probably $7 a pop and it would break up the massive amount of green and help soften it a bit.

I feel the blow is softened by the last part of our letter that invites our tenants to discuss with us any special circumstances.

Or how about top off their water softener salt?

After a while, they'll think you'll soften up, and let them get away with non payments because you're affiliated with them. 

This house has a well, water softener and house filter.