>>>i installed a stereo microphone pair inside the hive with the thought 
of using it for apidictor purposes....but mostly i use it to plug in 
headphones and hear inside the hive in stereo .<<<

Auto supply stores sell an inexpensive stethoscope with a long probe that can be used to listen to bees in hives, either through a hole in the hive or by probing around in the cluster in an open hive. 

allen