Hyperacusis 　One of the troubling symptoms of brain injury and higher brain dysfunction is anger. The hard word for this is irritability. They become irritable and start to get upset over the slightest thing. Many people complain that they have been angry before, but never so suddenly. 　The reasons for becoming angry vary from person to person. However, the primary reason is brain damage. This is why so many people become frustrated and lose their temper. Of course, there are also psychological issues and environmental influences. 　First, it is a good idea to look for triggers. 　One such trigger is sound. 　Often, when the brain is injured, hearing becomes hypersensitive. Symptoms include being startled by loud noises and yelling at them, not liking the sound of talking on the train or young people chatting, and saying, "Shut up! 　Others are startled when someone speaks to them suddenly, even if it is not loud. Others are annoyed not by the loudness of the sound, but by the high-pitched voices of children or the clattering of washing dishes, and they cannot concentrate on the work they are doing and end up yelling at the person. Strangely, or perhaps understandably, they seem to be fine with the sounds they make. 　These symptoms are seen not only in brain-injured people, but also in autistic people, and they know they don't like the sound because they can see the "ear blocking". There is still little awareness of this condition among specialists, and there is no good treatment for it. 　The most common remedy is to listen to one's favorite music through earphones, earplugs, or ear muffs for soundproofing. Although a bit expensive, noise cancelling earphones and headphones are also available.