The CMU Pronouncing Dictionary
A machine-readable pronunciation dictionary for North American English that contains over 100,000 words and their transcriptions.

Dictionary of English Phonesthemes Part 1
Relation of word sounds to meanings.

Roger's Reference - A Complete Homonym and Homophone Dictionary
Dictionary of words that are phonetically identical but which have different meanings. Now includes over 5000 homonyms and homophones, with meanings and cross-references.

AsifSound vs. Spelling - American Dictionary
Spelling glossary indexed by its abstract grouping pronunciation (=Asifsound). AsifSound consists of 12 sound symbols. This is made from CMU Pronouncing Dictionary.

American Homophones
List of American English words that sound the same (or very nearly the same) but are spelled differently.