Yelling or speaking may cause a spasm of one of the vocal cords which will cause the voice to become deep and raspy. Hoarseness is the next step in the progression. The parathyroid glands produce a hormone that helps regulate the calcium levels in your blood. Without going into too much detail here, if there is too much phosphorus in your body, the parathyroid hormone causes a release of calcium from your bones in an attempt to balance the two minerals. Smoking is a major cause of hoarseness.
Smoke irritates the mucous membranes and vocal cords.
Dust and strong vapors are additional possibilities. A cold may give you laryngitis, which sometimes prevents you from speaking at all. Avoid raising your voice to be heard, for instance to overcome outside noise, traffic, kids yelling, etc., as your voice isn't accustomed to it. A very dry environment may affect your throat, so drink plenty of fluids to keep your throat moist. Jet planes, very dry climates and many homes in the winter are examples.