Blocks infrasound

He stepped between the hound and me and lifted his left hand as the thing stood there for a second, dripping slime onto the ground beneath it and seething. Dozens of little mouths lined with serrated teeth opened along its flanks, gasping at the thick summer air as though it was something that the creature found only partially breathable.
Then the cornerhound crouched, its body turning toward us with serpentine fluidity. The cluster of tentacles around its head began to quiver and undulate in weird unison, the motion becoming more and more energetic, and a weird moaning sound erupted from the creature, descending swiftly down the scale of audible sound until the tentacles all undulated together in a single quivering movement, and suddenly flew forward at the same instant, with a sound so deep I could feel it more than hear it.
The old man lifted his hand with a single sharp word, and a wall of pure arcane power blazed into light between us, its surface covered in sigils and formulae and runes I had never seen before, a wall of such density and complexity that it made me feel young and clumsy for the first time in years.
Something hit the wall with a visible impact, sending out ripples of energetic transfer through its surface, making it suddenly opaque with spreading concentric circles of light, and the ground quivered so sharply that it buzzed and tickled at the soles of my feet clear through my shoes.
Ebenezar shouted, “Concentrated fire works best!”

Peace Talks Chapter 11, Page 91


I staggered, suddenly dizzy and weary from throwing the three energy-intensive spells back to back. I stumbled and had to lean on my staff to keep from falling, but I made it to Ebenezar’s side and helped him sit up.
“What happened?” I asked him.
His voice came out rough. “Infrasonic attack. Like a tiger’s roar. Super-low-pitched notes, below what humans can hear, capable of making your organs vibrate. Can have a bunch of effects …” He blinked his eyes several times, owlishly, and then said, “Hell of a thing to try to stop. Help me stand up.”
I did, drunkenly. “How tough are these things?”

Peace Talks Chapter 11, Page 93