dʒˈænsən wʌz bˈɔːɹn ɪn ˈɔɹɪndʒ, kˌælɪfˈoːɹniə, ænd ɹˈeɪzd ɪn hˈʌntɪŋtən bˈiːtʃ, kˌælɪfˈoːɹniə, ɡɹˈædjuːˌeɪɾɪŋ fɹʌm fˈaʊntɪn vˈæli hˈaɪ skˈuːl ɪn fˈaʊntɪn vˈæli, kˌælɪfˈoːɹniə.
Janssen was born in Orange, California, and raised in Huntington Beach, California, graduating from Fountain Valley High School in Fountain Valley, California.