The correct spelling of the word "Concordes" is with an "e" after the letter "s". This is because "Concordes" is the plural form of the noun "Concorde", which refers to the supersonic aircraft that traveled faster than the speed of sound. In IPA phonetic transcription, the word would be pronounced as /ˈkɒŋkɔːdz/ with the stress on the second syllable. The "s" at the end of the word would be pronounced as a voiced "z" sound due to being preceded by a vowel sound.