Submitting Affidavits to the Court
Affidavits are merely sworn statements under oath and can be submitted in any hearing, provided the judges allows it, like any other paper. However, in some cases, it has to be submitted as part of a motion, or at least relevant to a motion scheduled for that day. In a hearing a motion can be made verbally, therefore, affidavit thereupon may be made.
Having said that, it may also depend upon the court's rules too. I don't know about MA, but in general there is no bar to submitting affidavit.
Similarly, a motion can be filed in the court too (the judge permitting). This is why if the motion/affidavit is "controversial" which the judge may block from filing, it would be much more desirable to file ahead of the hearing so as to pre-empt the judge's obstruction.
A few more important points that you don't want to learn the hard way:
1. An affidavit from you or someone else there can not really be legally rejected by the judge unless it is irrelevant (though I hear they do this). You have the right to present any testimony, evidence and witnesses you want to within reason. If it is from someone not there then the opposition (or you) can object on the grounds that the person is not there to be cross-examined, and so the affidavit could be totally one-sided. This is a valid argument and can get it rejected.
2. It is a violation of due process to allow any motion that could cost you money, property, children time and other valuable "rights" you have without proper notice. This is a constitutional issue of "due process". The judge can wave the usual ten days notice (Mass. CRP) (in theory if this is irreparable harm, though the bar is much lower). However, you must get SOME notice! Otherwise it is a legal ambush and you can not be prepared with testimony, evidence and witnesses to defend yourself. In this case this would be a due process violation making the judge lose jurisdiction and making any resulting order from that hearing VOID. I have experienced about 6 of these kinds of biased orders where the opposition pulls out a motion not noticed at the hearing. Even when this is asked orally without a formal written motion if it is not related to the motions for the day you MUST object IMMEDIATELY. If you allow it to be heard you are likely waiving your right to notice!!!
The thing to do is:
a) Object on the grounds of no notice = due process violation and no preparation
b) Casually look for the certificate of service in the docket and point to the fact that there is none. This is showing that the DOCUMENTATION will show the judges error and due process violation. Not certificate of service? Then the motion can not be heard!!
c) Accuse the opposition of civil rights violations with a "ambush" motion denied to deny you your right to "whatever they are asking for" and point out that the judge loses jurisdiction and is personally liable if he even has a hearing or issues any order regarding this matter (He can try to pretend it is a Sua Sponte order though).
If the judge still allows this unnoticed motion to be heard you should state to the judge that you "take exception to this" and do not consider and hearing or order on this to be legally valid or binding on you or anyone in any way as a result of the due process violation. (GET IT ON THE RECORD that you object at least twice. BTW get the start and end tape numbers whenever you can from the clerk as well as keeping time if you can, so they can't drop this stuff out with audio editing as easily (as they have been known to do).
If you do not KNOW your rights AND ASK FOR YOUR RIGHTS you HAVE NO RIGHTS!!!
They are waived just by participating in these unlawful hearings.