Dear Native English Speaker, please help me pronouce this word correctly?

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I listen to this word: "wondered". According to my taught rule, you must pronounce ed of this word as /d/ , it means / 'w?n.d? r d/ but the sound that I listen to is very different. It sounds like /'w?n.did/. I upload the speaking file as follows: http://www.mediafire.com/?2z302yden373bu9 Please help me explain this situation. Thanks in advance