Obviously, the CMU pronouncing dictionary is using the Arpabet. The Arpabet has the advantage that it is possible
“to represent phonemes with ASCII characters.”
But today, the UTF-8 standard is becoming more and more common. In my opinion, there should be a discussion to switch from Arpabet/ASCII to IPA/UTF-8. The IPA is easier to read than the Arpabet. And UTF-8 should be backwards compatible to ASCII (at least, as far as I know).
Tags: dictionary, IPA, UTF-8