APPARATUS AND SYSTEMS FOR AUDIO AMPLIFICATION, NAMELY, PORTABLE MEGAPHONES, PUBLIC ADDRESS SYSTEMS, AUDIO SPEAKERS AND RECHARGEABLE HANDS-FREE VOICE AMPLIFIERS, AND RELATED ACCESSORIES THEREFOR, NAMELY, PORTABLE AUDIO SPEAKERS, HEADSETS FOR SUPPORTING MICROPHONES, MICROPHONES, WIRELESS MICROPHONES, STICK MICROPHONES, ELECTRICAL CHARGERS FOR CHARGING PORTABLE MEGAPHONES, BATTERIES, AND SPECIAL CARRYING CASES FOR PORTABLE MEGAPHONES