foghorn
n.— «“Olive, don’t use foghorns,” Convergence Contact Centre trainer Nilanjan Roy tells Olive Watson alias Mithu Malik. “Foghorns,” for the uninitiated, are the “hmms” and “ahaas” that punctuate tele-conversations.» —“Concise Desi Dix” by Nikhat Kazmi Times of India (New Delhi) July 13, 2004. (source: Double-Tongued Dictionary)