They may not be able to speak up, or it may cause discomfort. Lots of medical things can go wrong that affect speaking, some of which are pretty common. For instance, many things that cause repeated episodes of coughing get be made worse by loud talking. Some things may make getting any volume truly impossible, like paralysis or extreme weakness of the muscles controlling the vocal cords. That’s one’s not exactly a common problem, but not a rarity, either.
I have vocal cord problems that don’t have a big effect on how much volume I can produce, but do make my voice really unpredictable. That’s led me to notice that people who would take pains to avoid judging a person on uncontrollable aspects of appearance will still somehow think of a person’s voice as clear reflection of character and personality. While such impressions have something to them, there can be a lot of complicating factors. (The pamphlets available in my ENT’s office suggest that many patients with diseases or disorders affecting voice production find those conditions to be a severe cause of social distress.)
