The spelling of the phrase "art deflected" is determined by the International Phonetic Alphabet (IPA). The first word, "art," is spelled with the sound /ɑrt/, which is pronounced as "ah-rt." The second word, "deflected," is spelled with the sounds /dɪˈflɛktɪd/, which is pronounced as "dih-flek-tid." These phonetic transcriptions help to accurately depict the sounds of the words, allowing for clear communication and understanding of the spoken language.