Foghorn Voicehorn

You know how sometimes having a cold lowers your voice? Well, for the past several weeks I’ve had some funky sinus/throat thing happening, and this morning I woke up sounding like a foghorn. So I went down to the piano and found that I could hit three full notes lower than I normally can.

I wonder if there’s a way to artificially reproduce that effect without having to be sick. It would be really useful for singers, and anyone who wants to imitate Barry White or Darth Vader.