Grukking

Sometime later I was awakened by loud grukking. The sound resembled off-key music made by a sharp-toothed orangutan blowing spit through a twisted copper pipe. In other words, indescribable unless you hear it yourself.
-copied from here.

I copied this passage because it explains a word used by Poul Anderson:

"This was a chilly fall day. Wind boomed across stubblefields and the grey heath beyond them. Clouds hastened through an ice-pale sky where a flight of storks was outward bound, high and high above. Close down, some ravens flapped black and grukking. Off on one side lifted a wood, leaves ablaze in red, russet, brass, bronze, ripped loose and whirled away by the blast. Afar northward, a steel glimmer bespoke the sea." (Hrolf Kraki's Saga, p. 124)

Only three senses here but a vivid descriptive passage nevertheless.