We bought a new house a year ago and whenever the upstairs toilet is flushed you can hear a dripping sound downstairs below. How can that drip/sound be stopped?

That could be a little bit water that was left over from the flush that's dripping past the sanitary tee in the stack. Nothing to worry about. If you have PVC drainage the sound's always louder then if you had cast iron. Cheers, Tom

I think Tom is correct, if there was a leak you'd know it by now. Most homes do not have insulation around drain pipes and PVC can be loud. I am doing a bath right now and I usually insulated the drains and vent stack before I drywall. In your case that probably is not an easy option now.