“Hearken,” meaning “to listen,” comes from the Old English word “heorcnian,” which is also related to “hark” (which means “to listen with focused attention”). “Hark” appeared in the 12th century, but “hearken” didn’t show up until the 16th century, and lexicographers attribute the “ea” vowels to the association with “hear.” “Hearken” isn’t commonly used today, but there’s still some use of the phrasal verb “hearken back” as a synonym for “call to mind” or “remember.” For example, “The retro-infused music of Bruno Mars hearkens back to the golden days of soul, funk, and disco.”