Pronunciation: [hˈa͡ɪ jˈe͡ɪŋ] (IPA)
Correct spelling for the English word "hi yaing" is [hˈa͡ɪ jˈe͡ɪŋ], [hˈaɪ jˈeɪŋ], [h_ˈaɪ j_ˈeɪ_ŋ] (IPA phonetic alphabet).
Correct spelling for hi yaing