The words told, tolled sound the same but have different meanings and spellings. Why do told, tolled sound the same even though they are completely different words?
The answer is simple: told, tolled are homophones of the English language.
Past tense and past participle of tell1.
Simple past tense and past participle of toll.
Definitions from The American Heritage® Dictionary of the English Language, 4th Edition, from Wiktionary, Creative Commons Attribution/Share-Alike License and Wordnik.
Homophones (literally "same sound") are usually defined as words that share the same pronunciation, regardless of how they are spelled.