The transcription conventions we use conform to the International Phonetic Alphabet (IPA). The transcriptions you'll find in this website are similar to those in Oxford dictionaries, for instance. For the sake of consistency, we'll conform to these conventions, although in American English, vowels and diphthongs may be pronounced differently.
A special adaptation we'll be using concerns the transcription of post-vocalic /r/ as in the words car, here, air... In this case, a superscript ʳis used, and the words in question are transcribed as /kɑːʳ/, /hɪəʳ/,and /eəʳ/.
In certain contexts, the sounds p, t and k are pronounced with an additional "puff of air" and are said to be apsirated. This creates the further difficulty of knowing when these sounds are aspirated or unaspirated.