Many have felt that morning croaky voice, especially when they have not had enough rest. Lack of sleep not only leaves the cords puffy and swollen (which causes the deep croaky sound) but robs the body of the chance to heal the cords. Sleep is when the body repairs itself, and depriving the voice of that allows damage to accumulate. Also, swollen cords make it more difficult to sing cleanly, and the extra thickness means the singer must work harder to get to pitch.
Water is another critical component. Most everyone knows the voice requires water but not necessarily why. The vocal cords have an outer layer of mucosal tissue that needs a thin layer of mucus. If this mucus becomes thick because of lack of proper hydration, then the cords are exposed to more stress and damage. The singer's vocal cords are vibrating hundreds of times a second, even more than 1,000 times in an upper female range. Thin mucus stops irritation from occurring; thick mucus does not.
One misunderstanding is the idea that the water you drink goes directly on your vocal cords. The cords are protected from food and drink during the swallowing process, so water must go from the stomach and through your system before reaching the vocal cords. This can take more than an hour, so be sure to start your water intake well before singing.
The way to get water directly to the vocal cords quickly is to use steam. Either breathe the steam of a hot shower or breathe from a facial steamer. (Don't get too close; you don't want to burn the cords.)
Vocalize is another obvious component, but you need to do it correctly. There should be a few phases to your daily vocal workout. The first is warming up, getting the ligaments and muscles of the voice ready for the work ahead. Be careful not to sing too loudly or powerfully yet; that will come later. Gentle glides up and down through your range are a great way to get everything ready.
The next phase is working on vocal quality. Sustains, vibrato, range, quality of tone, and flexibility are all great elements to work on. You still don't want to work on power, as this can throw out the other elements you are trying to balance and improve. Once the voice is warmed
up and working well you can finally concentrate on power and repertoire.
John Henny is a leading coach for vocal technique in the music industry. His techniques keep the voice healthy and improve overall sound. Follow him on Twitter @johnhennyvocals, or visit