earphone jack

Hello my unit in SDS100. I have to use a powered external speaker to listen to it since the loudness does not make it loud enough to hear. I need a powered earpiece as well, to be able to increase the volume to the earpiece and not just an external speaker. Does anyone make a solution for...

First a bit of history... I am a terminally ill individual with a disease similar to but much worse than Muscular Dystrophy. I have a severe hearing loss and glaucoma and am a semi-quadriplegic in a wheelchair. I bought the BCD536HP because it was (and still is with the BCD436HP) Uniden's...