Misophonia is a neurological disorder, and the word translates directly into "the hatred of sounds." People who suffer from it have different triggers and can be sent into a flight or fight mode, experience intense rage, and even thoughts of suicide when they hear these certain sounds. There isn't much known about it, and there is no cure.
It varies enormously from simply "getting annoyed" by a various sound. It has outstanding affects and the rage cannot be controlled and can trigger violence, or a desire to do so, and the affected person may have to leave the situation. Whereas a person may be able to control their frustration if it is a simple annoyance.
I suffer from it, and it is a nightmare. Schoolwork in a large class of people whom talk is beyond annoying. It can bring you to tears of anger, disrupt you, ruin your entire day because of how angry you become, put large strains on your everyday relationships and make it a large battle to simply keep calm in your life for even one day. It also makes you anti-social because you have to withdraw from social activities in order to keep sane.
For a long time I wondered why it was difficult for me to be happy and excited everyday. I still got angry, and didn't know for many years what it was. It made life constantly aggravating. It made everyday life situations unbearable; it made life unbearable at times.
Once I found I had misophonia, I brought in ear-plugs to tests and listening to music of my choice to drown out my triggers. Alas, there are times I cannot do that. Which I must be in a large and noisy group, which often ends in massive anger which can carry over to other situations and can ruin your day.
The reason why you shouldn't ignore this is because it is a legitimate neurological disorder which affects many people. Whether or not you personally see it as a "big deal" or not does not mean that people whose lives you are affecting see it in the same light. It affects a person's emotional stability, their happiness and or lack of it, their own concentration and the strain that gets carried over to other circumstances from a situation you may be able to control.
Please, acknowledge this disorder and who it may affect in your midst. Do not be ashamed or afraid to blow your nose, or to behave in a slightly quieter way, to speak quieter or refrain from speaking when there are others attempting to work effectively. Raise awareness for misophonia by first educating yourself, and through helping those who suffer by refraining to cause the noise that triggers them, can help alleviate the commonness of this disorder and our extreme reactions.