ɪn nˈaɪntiːnhˈʌndɹɪd sˈɛvənti ˈeɪt, sˈɑːnmɚ wʌz nˈeɪmd hˈɛd kˈoʊtʃ ʌvðə mˌɪnɪsˈoʊɾə nˈɔːɹθ stˈɑːɹz ʌvðə nˈæʃənəl hˈɑːki lˈiːɡ ˌɛnˌeɪtʃˈɛl ænd wɛnt ˌɔn tə θɹˈiː dˈɪfɹənt kˈoʊtʃɪŋ tˈɛnjɚz wɪððə tˈiːm nˈaɪntiːnhˈʌndɹɪd sˈɛvənti ˈeɪt nˈaɪntiːnhˈʌndɹɪd ˈeɪɾi θɹˈiː, nˈaɪntiːnhˈʌndɹɪd ˈeɪɾi fˈoːɹ nˈaɪntiːnhˈʌndɹɪd ˈeɪɾi fˈaɪv, ænd nˈaɪntiːnhˈʌndɹɪd ˈeɪɾi sˈɪks nˈaɪntiːnhˈʌndɹɪd ˈeɪɾi sˈɛvən.
In 1978, Sonmor was named head coach of the Minnesota North Stars of the National Hockey League (NHL) and went on to three different coaching tenures with the team (1978–1983, 1984–1985, and 1986–1987).