ear (n.1) Look up ear at Dictionary.com
"organ of hearing," Old English eare "ear," from Proto-Germanic *auzon (cognates: Old Norse eyra, Danish øre, Old Frisian are, Old Saxon ore, Middle Dutch ore, Dutch oor, Old High German ora, German Ohr, Gothic auso), from PIE *ous- with a sense of "perception" (cognates: Greek aus, Latin auris, Lithuanian ausis, Old Church Slavonic ucho, Old Irish au "ear," Avestan usi "the two ears").

The belief that itching or burning ears means someone is talking about you is mentioned in Pliny's "Natural History" (77 C.E.). Until at least the 1880s, even some medical men still believed piercing the ear lobes improved one's eyesight. Meaning "handle of a pitcher" is mid-15c. (but compare Old English earde "having a handle"). To be wet behind the ears "naive" is implied from 1914. Phrase walls have ears attested from 1610s.
ear (n.2) Look up ear at Dictionary.com
"grain part of corn," from Old English ear (West Saxon), æher (Northumbrian) "spike, ear of grain," from Proto-Germanic *akhaz (genitive *akhizaz; cognates: Dutch aar, Old High German ehir, German Ähre, Old Norse ax, Gothic ahs "ear of corn"), from PIE root *ak- "sharp, pointed" (source of Latin acus "husk of corn," Greek akoste "barley;" see acrid).