I had a relative that had that same type of coarse voice and when she finally listened to me, she was cured and it never came back. Many of us a targeted by toxic dust and fungi. Even bacteria can cause this too as some harden. A Mabis steamer with manuka honey, pink Himalayan sea salt, and Braggs apple cider vinegar. Honey kills over 200 bacteria and gram negative ones too, vinegar kills fungi, salt does both and ionizes the particles to further enhance their absorption. It also gets rid of wrinkles, clear lungs of any COPD problems, and make tissue more elastic which is retaining proper moisture. Hope he tries this, it does wonders.