The words baron, barren sound the same but have different meanings and spellings. Why do baron, barren sound the same even though they are completely different words?
The answer is simple: baron, barren are homophones of the English language.
A British nobleman of the lowest rank.
A nobleman of continental Europe, ranked differently in various countries.
A Japanese nobleman of the lowest rank.
Used as the title for such a nobleman.
Not producing offspring.
Incapable of producing offspring.
Lacking vegetation, especially useful vegetation.
Unproductive of results or gains; unprofitable: barren efforts. See Synonyms at futile.
Definitions from The American Heritage® Dictionary of the English Language, 4th Edition and Wordnik.
Homophones (literally "same sound") are usually defined as words that share the same pronunciation, regardless of how they are spelled.