YOU SAID:

he heard he say someone else's name

INTO JAPANESE

彼は他人の名前を言っているのを聞いた

BACK INTO ENGLISH

I heard him say someone else's name

INTO JAPANESE

彼が他の人の名前を言うのを聞いた

BACK INTO ENGLISH

heard him say someone else's name

INTO JAPANESE

彼が他の人の名前を言うのを聞いた

BACK INTO ENGLISH

heard him say someone else's name