The phenomenon of aggressive throat clearing in public settings is a subject best analyzed by behavioral psychologists. I myself think that much of the barking and hacking one hears at a concert is an unconscious expression of profound psychological discomfort, a discomfort brought on by feeling caught in a confined space with a large number of people all sharing emotions of extreme delicacy. The music expresses an intimacy that is simply too much for some audience members to tolerate in a public setting. They very likely are not even aware of their unease, but they reach out desperately for an emergency valve, an escape hatch from the confines of their deep feelings of internal discord. So the loud cough, most likely completely unconscious, is a way of saying “I can’t handle this, folks. You all may be crowding round Mahler’s deathbed for one final intimate confession. You may be letting Debussy whisper opium secrets into your ear. Perhaps you like being ravished by Takemitsu’s lush penumbras. BUT I AM OUTTA HERE!”
John Adams, “Hocking a Hooey at the Concert”