Phonetic Alphabets
Phonetic alphabets are sometimes known as pronouncing orthographies, because they extend the number of orthographic characters in the alphabet to provide a new one for each of the possible 44 or so sounds/phonemes in the English language.

Edwin Leigh invented the idea of a pronouncing orthography in 1854.It was sometimes called Pronouncing Print.

Leigh's pronouncing orthography was inspired by Isaac Pitman's 1844 Fonotypy or Pnonotypic Alphabet which became famous as Pitman's "Shorthand."

One difficulty in using pronouncing orthographies is that historically they have been published in print, which is sadly mute on the exact sounds of each character. (That turns out to be an advantage when the goal is to respect dialect differences in pronunciations.)

Today audio recordings can provide standard English sounds of single- and multi-letter phonograms, along with the key words used to describe them in print, for example /c/ as in cat.

The most authoritative pronouncing orthography is the International Phonetic Alphabet (IPA), which fortunately is now available online with recordings of their sounds here.

Another very important phonetic alphabet is the CMU Pronouncing Dictionary (or CMUdict). Created by the Speech Group at Carnegie Mellon University, CMUdict s an orthographic to phonetic mapping of English words as pronounced in North America. The CMU Speech Group built CMU Sphinx, open-source tools for automated speech recognition (ASR), and CMU Festival, which does speech synthesis or text-to-speech (TTS). CMUdict is a corpus for building statistical grapheme-to-phoneme models that can generate pronunciations not yet in the pronouncing dictionary, which already has over 125,000 words.

CMUdict uses a modified version of the ARPABET (or ARPAbet) a set of phonetic transcription codes developed by the Advanced Research Projects Agency (ARPA) as a part of their Speech Understanding Research project in the 1970s. Instead of inventing new orthographic characters like the IPA, ARPAbet represents phonemes and allophones of General American English with distinct sequences of ASCII characters.

Some commercial dictionaries offer free online access to pronunciations of their words, along with excellent definitions, examples of their use,