Children can't use it. The reason given for this is that their voices are too high! This is rubbish and I started using speech recognition when I was 9. The technology has developed a lot so it should be even easier now.
When using it you have to talk REALLY LOUD! When I was at school this was one of the reasons teachers were reluctant to let me use it in the classroom. However, I am using the software right now and I'm talking barely above a whisper. When using it in lessons, I was certainly never any louder than the guys gossiping at the back of the classroom!
Training takes for ever. With the latest versions of software Dragon NaturallySpeaking only takes about 30 minutes to do initial training.
You have to speak each word individually like a robot. Wrong! In fact it works much better if you speak as naturally and as fluently as possible.
You have to speak really slowly. Wrong again, it's better if you speak at a normal pace. In fact, if you pronounce each individual word properly, you can speak as fast as you like. Usually, when I am dictating, I speak a lot faster than I would in normal conversation.
When you are dictating, the room has to be totally silent. This was a concern I had when using speech recognition in a busy classroom. However the microphones used for speech recognition generally tend to be proximity microphones which only pick up noise close to. Unless somebody's being particularly loud next to you, the odds are, recognition will not be affected.
You are not allowed to use speech recognition in an exam. False. The access arrangements for GCSE and A levels do allow it and it is covered in the Regulations. Universities also allow it. Schools and universities sometimes make a meal out of this one but persevere as it is permitted but not many people know this.