Reflux is an uncomfortable condition for anyone experiencing it, but it can also lead to changes in voice production.  The acid can damage the tissue in the voice box, but even if the tissue is undamaged, the irritation can result in people changing how they use the muscles in the voice box, resulting in hoarseness.  There is excellent information available at this website http://pvcrp.com/throat_problems___gastro_esophageal_reflux.php that highlights the importance of getting gastro-esophageal reflux under control.