I get this question at least once a week: "what should I do if my voice is weak and I have to give a presentation/talk/performance?" First of all, if you have full laryngitis, as in complete loss of voice, it won't come back until it's good and ready (and of course, you should consult your doctor anytime you have questions about your voice). I advise my clients to plan on at least 3 days of full vocal rest, and to re-schedule their obligations until after that. If, however, your voice is merely hoarse (which I will define here as rough, strained, and set at lower volume), you might be able to initiate at least a partial recovery on your own. Here are some things you can try:
1) Set aside a period of dedicated vocal rest. Set a timer for 3 hours of complete silence. Commit to this simple act of relief, and don't stop until the time is up. Let your vocal cords calm down and settle. You can also take some Ibuprofen to help with inflammation (consult your doctor before trying this).
2) Drink a tall glass of water. Your voice needs plenty of hydration to function at full capacity. Make a strong cup of Throat Coat tea, and let it cool down a bit before you drink it. The soothing herbal formula should continue to soothe and calm inflammation in your throat. You can try some throat lozenges during this time as well.
3) Focus on breathing deeply, while relaxing and muscles in the throat that are tense. Close your eyes and feel everything relaxing and settling down into its proper place. Keep allowing this release of tension as you go through your day
4) When your period of vocal rest is done, do some light humming, in a vocal range that feels the most comfortable. Don't reach too high, and don't growl too low. Find the center of your voice, and start there.
5) Work through your speech, song, or presentation at low volume, remembering to breathe deeply into the diaphragm for support. Slowly increase volume, and see how it feels. Make sure your posture is aligned and comfortable. Don't strain your neck forward, or tense your back. Hopefully you will begin to feel stronger, but save your full voice for the actual event.
Many of my clients book "emergency" sessions if they wake up hoarse on the morning of a big event. I run them through simple vocal exercises, but not before I've advised them to do this protocol. Try it and see how it feels.... you might work your way back!