The Spanish verb oír ('to hear') comes from Latin audire ('to hear'). As Latin evolved into Proto-Romance, audire first changed to *odire and then to *oire, with the 'au' sound simplifying to 'o' and the 'd' eventually disappearing between vowels. This development finally led to Spanish oír, maintaining the same meaning of 'to hear' throughout its history.

Some related Spanish words include oído ('ear' or 'hearing'), oyente ('listener'), and oiga ('listen!' or 'hello?' when answering the phone). All these words share the same root and relate to the act of hearing or listening.

English words related to oír come from the same Latin root audire and include 'audible', 'audience', 'audio', and 'auditory'. While Spanish simplified the 'aud-' sound to 'o-', English borrowed these words more directly from Latin, preserving the original 'aud-' sound. All these words maintain a connection to hearing and sound.