I think using a couple of digital voice recorders as back up should fix your concerns for the most part. In theory spirits tend to consume electromagnetic energy when they manifest causing the device their drawing from to malfunction or die. As an avid ghost hunter this bullshit has happened to me a lot but if it’s evidence your looking for I suggest stepping up your game. http://www.ghoststop.com/Default.asp is where I buy all of my equipment and the prices are pretty decent comparing it to other online vendors. On a further note you should look into spirit box communication. I have discovered some interesting things regarding spirits and ritual with the use of a spirit box. Lol, trust me E.A. once you really begin to delve in spirit box communication you will see the validity to your message once you talk to and hear the helpless spirits who died believing in christianity. They are all lost crying and begging for help and much worse. From my experience with this device and devices like it I have only come up with one conclusion and that is the afterlife is only reserved for the elite, the best, The Living Gods of this World. If you ever experiment with this device you’ll see it for yourself once you begin to separate the weak from the Gods. Keep doing what your doing E.A. because if you don’t know this already, your saving lives.