The apnea-hypopnea index, like the apnea index and hypopnea index, is calculated by dividing the number of apneas and hypopneas by the number of hours of sleep.
ðɪ ɐpnˈiəhˌaɪpoʊpnˈiː ˈɪndɛks, lˈaɪk ðɪ ɐpnˈiə ˈɪndɛks ænd hˌaɪpoʊpnˈiː ˈɪndɛks, ɪz kˈælkjʊlˌeɪɾᵻd baɪ dᵻvˈaɪdɪŋ ðə nˈʌmbɚɹ ʌv ɐpnˈiəz ænd hˌaɪpoʊpnˈiːz baɪ ðə nˈʌmbɚɹ ʌv ˈaʊɚz ʌv slˈiːp.