The Low Mutterer (commentus irritatus)

Low Mutterers are a funny breed. They appear quite normal and in fact, you may even be saying a silent thank you to the powers above when this species chooses to sit near you instead of a weirdo. However, by the time your prayer is over, that's when the weirdness starts and you know your prayers have been in vain and you have in fact been fooled.  Low Mutterers can be male or female and are characterized by low-frequency muttering, audible but almost under their breath.  After a few minutes of being subjected to this unique form of auditory torture, you may even start to believe this muttering may actually be some sort of important dialogue. You may strain to hear the words but they are always alas, just below the level of human hearing. These people could be muttering the cure for cancer or a new theory of relativity but after fellow passengers silence them with harsh glances, those breakthroughs are lost to science forever. If you find yourself in the presence of a low mutterer, ask them to speak up, if only for the sake of science and humanity.