模糊的條文，可以用合同外的證據解釋

如果合同條文模糊，在合同內和其他條文矛盾，合同外的證據可以用來解釋合同。這樣你的錄音，口頭證據之類的，就可以拉進來考慮了。這是普通法合同法的原則。http://en.wikipedia.org/wiki/Parol_evidence_rule

但是還要看你在哪個州。Wikipedia: "In a minority of U.S. states, (Florida, Colorado, and Wisconsin), the parol evidence rule is extremely strong and extrinsic evidence is always barred from being used to interpret a contract. In most jurisdictions there are numerous exceptions to this rule, and in those jurisdictions, extrinsic evidence may be admitted for the following purposes:
。。。
To aid in the interpretation of existing terms.[5]
To resolve ambiguity using the contra proferentem rule.
。。。
To correct mistakes."

但是證明這些，不懂合同法的各方麵的聯係，你自己去說，說不來的，你不請律師，人家以為你是胡說，誰會上心？非常技術性的討論，隻有出庭告。