For the second time this year my voice has been f*cked up for a couple of weeks. As I work speaking and singing to groups of people this is a pain in the arse. It feels like it takes several weeks to get rid of a minor sore throat, because every couple of days I strain it again trying to use my voice, and it gets hoarse and sore again. Are there things I can do to a) prevent it b) alleviate it when it has happened?