Audio Monitoring Vs Recording? Legal Difference?

In the IPVMU class, we are discussing legal issues with audio recording. In the US, there are laws that vary state by state (see this guide).

A question was raised about audio monitoring, i.e., listening but not recording. Is this legal? Or is it more often legal in jurisdictions?

John, I was searching for the guide and can't seem to find it.  Is it still available?  The link just goes to the main page.  Thanks!

Here is an archived link to that guide. I've updated it in the original post above as well.

Thanks for bringing that to our attention, Joseph. The link is now fixed. Please let me know if there is anything else I can do to help.

From what I was told in PA, monitoring or recording is legal unless two-party's consent.