The word "Hyoideal" is an uncommon term with an unusual spelling. Its pronunciation is /haɪəʊɪˈdiːl/, which can be broken down into individual sounds using the International Phonetic Alphabet. The first two sounds, /haɪ/ represent a diphthong and are pronounced like the word "high." The third sound, /əʊ/, is another diphthong, pronounced like the word "oh." The next sound, /ɪ/, is a short "i" sound like in "pin." Finally, the last two sounds, /diːl/, represent a long "e" sound followed by an "l" sound. Thus, the spelling of "Hyoideal" reflects its unique pronunciation.
Connected with the hyoid bone.
Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874.