Microbicidal air filter for use with an air passageway, which includes an immobilization network including fibers having substantially embodied therein an amount of at least one antimicrobial agent sufficient to substantially immobilize, retain and kill microbes suspended in a volume of air moving through the air passageway. Each of the slots has a generally C-shaped configuration and opens to the peripheral edge of the panel. The gooseneck mechanism allows for the relative easy placement and then securing of the positioner at a desired location. The positive and negative terminal electrodes have dimensions substantially equal to those of the positive and negative electrode collectors, respectively. The command input device is adapted to receive commands from a user as voice commands, and the processing device comprises a filter adapted to filter voice commands against high frequency losses and frequency distortion caused by the mammal body.