Dreaded Phlegm. All vocalists and speakers hate phlegm. Avoid clearing throat by coughing and grunting. Sounds awful, however swallowing is far better. Phlegm is also a 'protector'. The body will produce further phlegm to protect the true vocal folds if there is vocal trauma (swelling, scratching etc). It is also triggered by dietary intolerance however, would make sure the cause isn't from vocal trauma first.