Not sure why my comment merited a downvote. In any case, quoting from Mass law:

https://malegislature.gov/Laws/GeneralLaws/PartIV/TitleI/Cha...

    The term ''interception'' means to secretly hear, secretly record, 
    or aid another to secretly hear or secretly record the contents of
    any wire or oral communication through the use of any intercepting
    device by any person other than a person given prior authority by 
    all parties to such communication.

    The term ''contents'', when used with respect to any wire or
    oral communication, means any information concerning the identity
    of the parties to such communication or the existence, contents,
    substance, purport, or meaning of that communication. 

So first question, "devise a mechanical device" -- violates. Second, "write notes", no. Third question, "secretary record" -- no.

Fair enough, it seems the watch would be an 'intercepting device' and thus all parties would need to agree for any party to use the device for the summary function.

  Not sure why my comment merited a downvote.