The spelling of the word "OHRDTSTA" can be explained using the International Phonetic Alphabet (IPA). The first sound, "oh" is represented by the IPA symbol /oʊ/ which is a diphthong sound consisting of the vowels "o" and "h". The second sound, "r" is represented by the IPA symbol /ɹ/ which is the English "r" sound. The third sound, "d" is represented by the IPA symbol /d/ which is the voiced "d" sound. The final sounds, "ts-ta" are represented by the IPA symbols /ts/ and /tə/ which together make the consonant cluster "ts-ta".