effyleven see ferynn? I believe his answer is correct. Assuming your question was a genuine inquiry and not just a joke....the verb "entendue" is your first clue. The conjugated masculine form of the verb is spelled "entendu" in the past tense. It is good to question other learners but if there is not a DUO MOD present then research verb conjugations is my best advice. Bonne chance.
It's not grammatically necessary, but it makes the same distinction as between this (-ci) and that (-là) (although it can be used much more flexibly). http://french.about.com/od/vocabulary/a/suffix-ci.htm http://french.about.com/od/vocabulary/a/suffix-la.htm
Two separate issues here. "Entendre" generally means "to hear"; although it can mean "to understand", I believe that is quite formal and not a translation one would naturally go to.
As for "him", if you got this as an audio clue, then it should be accepted. If not, the "e" on the end of "entendue" tells you that the thing heard was feminine and could be either "her" or "it", but not "him".
Important point to note: When a verb in a compound form (passé composé, plus-que-parfait, etc) uses "avoir", rather than "être", the participle agrees with the object but only when the object occurs before the verb in the sentence.
"J'ai entendu la femme" = I heard the woman.
"Je l'ai entendue" = I heard her.
Let's look at some of the "tricks" The text "Je ne l'ai pas entendue cette nuit-là" made by the same developer which are: "I did not hear her it that night" and "I did not hear that night," What happens, is that when you give an answer of the two, if it does not accept that the system is predefined, in that instant, it does not accept it and re-write the other option to answer either agree and write the same that the system suggests to check, nor accepts it and it has made me a headache. Use the option to write the two answers together, as you would expect not the iva to accept either. I think that with this way of presenting the response options or TATA GOD will get it right. Naturally this has me confused, not like I know which of the two options is appropriate at a certain time. So I think no one will be able to learn a language. And I should clarify that this is not the first time that happens to me.