Armstrong acknowledged Aldrin's completion of the post-landing checklist with "Engine arm is off", before responding to the CAPCOM, Charles Duke, with the words, "Houston, Tranquility Base here.
ˈɑːɹmstɹɔŋ ɐknˈɑːlɪdʒd ˈɔːldɹɪnz kəmplˈiːʃən ʌvðə pˈoʊstlˈændɪŋ tʃˈɛklɪst wɪð "ˈɛndʒɪn ˈɑːɹm ɪz ˈɔf", bᵻfˌoːɹ ɹᵻspˈɑːndɪŋ tə ðə kˈæpkɑːm, tʃˈɑːɹlz dˈuːk, wɪððə wˈɜːdz, "hjˈuːstən, tɹæŋkwˈɪlᵻɾi bˈeɪs hˈɪɹ.