When I was...13 maybe 14 I started to have a light case of selective mutism. I started to notice that whenever I would talk I would be constantly interrupted or talked over, or whenever I even opened my mouth to speak people would roll their eyes or pull a annoyed face, before I could even say anything. My confidence took a huge hit and I didn't feel comfortable speaking to a lot of people, including my own mother. I would still talk in certain situations, like if I really had to, or with one or two friends that actually let me talk. But I was mostly silent with everyone else. It took 4 month for people to even notice, and when they did they would ridicule me to try and get me to talk. I started talking again, but only to get people to leave me alone. Update 5-6 years later and I still get talked over, and faces are made when I open my mouth. Nothing has changed.