I unlocked this in Hollywood in Hybrid mode, though the mode and map isn’t really the important part with this Achievement. Lucio’s Sound Barrier is uses an area of effect to heal you and your teammates, so you’ll need to identify an opportunity to use it affectively.
When you have an enemy about to use a super — D.Va’s exploding mech or Hanzo’s big, twisting dragons are damaging and are telegraphed — and when you have your teammates around you, hit Y to unleash Sound Barrier. It’ll soak up the damage from the enemy super and hopefully keep you all alive.
The Achievement will unlock when you’ve successfully absorbed 1,000 points of damage. Killing yourself, as I did, isn’t necessary. Oops.
Voila! Here’s how it all looks, keeping in mind we made the video using XboxDVR.com, so the Achievement doesn’t actually pop on-screen.