He also introduced cyclic cohomology in the early 1980s as a first step in the study of noncommutative differential geometry.
hiː ˈɔːlsoʊ ˌɪntɹədˈuːst sˈaɪklɪk kˌoʊhəmˈɑːlədʒi ɪnðɪ ˈɜːli nˈaɪntiːnhˈʌndɹɪd ˈeɪɾi z æz ɐ fˈɜːst stˈɛp ɪnðə stˈʌdi ʌv nˌɑːŋkˈɑːmjuːɾətˌɪv dˌɪfɚɹˈɛnʃəl dʒiˈɑːmətɹi.