I've always wondered what kind of a noise a disembodied spirit could make without any vocal cords or breath or any other earthly sound-producing mechanism.

How does the banshee sound ?" O'Keefe looked at me seriously.
"All right," he said.

"I'll show you." From deep down in his throat came first a low, weird sobbing that mounted steadily into a keening whose mournfulness made my skin creep.

And then his hand shot out and gripped my shoulder, and I stiffened like stone in my chair--for from behind us, like an echo, and then taking up the cry, swelled a wail that seemed to hold within it a sublimation of the sorrows of centuries! It gathered itself into one heartbroken, sobbing note and died away! O'Keefe's grip loosened, and he rose swiftly to his feet.
"It's all right, Professor," he said.

"It's for me.