Definitely keep recording. The spectrographs can show the formants of the vocalizations, but don't put too much weight in the opinion that they are all coyotes, particularly with the associated knocks. If you've heard the recordings from the Michigan Recording Project, they had pretty much the same things with knocks, whoops, ahhhh screams, chatter and outright shouting that sounds so human, most would be satisfied that's all it was. The circumstances is about all that would suggest otherwise along with a direct sighting.