The words attendance, attendants sound the same but have different meanings and spellings. Why do attendance, attendants sound the same even though they are completely different words?
The answer is simple: attendance, attendants are homophones of the English language.
The act of attending.
The persons or number of persons that are present.
The frequency with which a person is present.
Plural form of attendant.
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.