I understood your sentence that "a bird was singing outside and you listened its voice coming through your window". If my understanding is correct, I would say: 今朝、窓の外から鳥の声が聞こえてきました。 今朝、私は窓の外で鳴いている鳥の声を聞きました。 I hope this helps you.

Hi, I'm shunsuke, Japanese. I hope my answer will help you. Just translation of this sentence into Japanese is that "今朝、私は窓から入って来る鳥の鳴き声を聞いた。" Sorry, I couldn't understand that this sentence means either "bird is coming through window" or "a voice is coming through window", but this translation may have both meanings. In addition, if "my window" means "my room's window", you can change "窓から" into "私の部屋の窓から" . And we put "a voice of human being" into "声", but "a voice of animals" is usually put into "鳴き声" or "nakigoe". Sincerely yours.

Hi, i am not very strong in japaneese, but want to say about my view. :) I think if it formal form - its may be [Watashi wa.... kiita/私は。。。聞いた] kesa - may be kesa de after wa? Or may be before watashi.... You used heya de (in room), but in your english form nothing about it... [Itsu tori koe wa]... Is it main part? I dont think so... If its will be so - Tori no (koe) (is the birds can have voice?) WA mado kara kikoeta!(聞こえた) See for kanji [鳴く]. My version something like - Kesa de Watashi wa mado kara naku tori wo kiita. / 今朝で(this morning)私は(I am)窓から(from window)鳴く鳥(singing bird)を聞いた(heard)。