Here's another website that mentions two party consent on audio from a security camera company:

They list these states:
States with "Two party Consent" for audio recording

California - Two Party
Connecticut - Two Party
Delaware - Two Party
Florida - Two Party
Hawaii - Two Party
Illinois - Two Party
Kansas - Two Party
Maryland - Two Party
Massachusetts - Two Party
Michigan - Two Party
Montana - Two Party
Nevada - Two Party
New Hampshire - Two Party
Pennsylvania - Two Party
Utah - Two Party
Washington - Two Party

And I did find this from an Attorney's Website:

"A general rule is that if the people engaged in the conversation can reasonably expect their conversation to remain private, then the statute protects that conversation....in one case, bugging a private house with a hidden microphone violated state law because the residents inside reasonably expected their conversations to remain private.

Twelve states require, under most circumstances, the consent of all parties to a conversation. Those jurisdictions are California, Connecticut, Florida, Illinois, Maryland, Massachusetts, Michigan, Montana, Nevada, New Hampshire, Pennsylvania, and Washington."

So as you can see there is some difference in the information.

Here is another little something that I found interesting about one-party audio recording laws from another legal website:

"Federal law permits recording telephone calls and in-person conversations with the consent of at least one of the parties. See 18 U.S.C. 2511(2)(d). This is called a "one-party consent" law. Under a one-party consent law, you can record a phone call or conversation so long as you are a party to the conversation. ... Regardless of whether state or federal law governs the situation, it is almost always illegal to record a phone call or private conversation to which you are not a party, do not have consent from at least one party, and could not naturally overhear. In addition, federal and many state laws do not permit you to surreptitiously place a bug or recording device on a person or telephone, in a home, office or restaurant to secretly record a conversation between two people who have not consented."