There is something called Conversion Disorder which causes neurological symptoms but has no neurological cause and is said to be from stress, by a trauma for example. So by hearing something greatly disturbing to you may cause you to be unable to hear even though there is nothing actually wrong with your hearing.
You can also go blind, mute or even paralyzed in your whole body or just your legs or one arm etc. I have gone blind before for a short time. There was nothing actually wrong with me but I could not see.