young is a relative term, how old is he/she? It will not affect its hearing. However major caution, start this out slowly- many good hunting dogs are ruined by making them gun shy. Best to start out with a cap gun at a distance greater than 50'. If the dog reacts to the noise (positive or negative) don't you react. May sound silly but if you try to console the dog, if they act scared you only reinforce that there is something to be scared about.