I've left out an important point. Human infants are born with an ape-like vocal tract, that is, with a very high larynx, so that they can suckle and drink without drowning. It is only after six months that the larynx drops to its lower position to allow for speech and it is then that the epiglottis comes into play. It must be a very intelligent IM to have that much foresight in planning for language and speech. Sorry, but this reeks of design.