Really 1 shot from Glock 17 will make your hearing worse.Sure, you wont be deaf but still you will need hearing aids to hear properly. Suppressors suppress gun from 30-50 Db. Glock 17 is 159 Db and after suppressor is on it has only 109 Db. 140 Db already causes some noticable damage after 1 ms. One milisecond! 159 Db is 8 times louder( every 6 Db loudness doubles). So to save your hearing at self defense and you don't have time to put ear protection on you would need suppressor.