When you wake up in the morning the voice often sounds ‘woolly’. You have been drawing air back and forth over the mucous membranes all night; maybe you have even slept with an open mouth. This may have dried out the mucous membranes. When you wake up and speak, the dried out mucous membranes cannot make the rapid vibrations that produce a sonorous sound, causing the sound to be husky and irregular – known as the ‘morning voice’.
You should let the natural production of mucous take its course. The mucous membranes will soon be moistened and the voice will sound normal again. If you start to clear your throat, which dislodges the mucous o‪ff the membranes‬, they will only produce more to cover the exposed, dry area. This makes some singers clear their throat again, compelling the mucous membranes to produce yet more, which the singer dislodges again, and so on. The singer and the mucous membranes can keep each other occupied like this for the rest of the day.