You bet! Yes, it's similar to a bark but the nervous grunt is not used repeatedly like most warning barks would be as elk put distance between you & them. It's common for elk to use this grunt & stay right there looking for the elk they heard or feel is there. This sound is heard when a hunter has called elk to a certain distance & the elk gets to a spot they feel they should be seeing this elk, when they do not it's common for this elk to ask the elk they heard to show themselves.