Basic Systems:
ChatterVOX 6 Voice Speech Amplifier:
http://www.harriscomm.com/chattervox-6-voice-speech-amplifier.html
The ADDvox7 Voice Speech Amplifier:
http://www.harriscomm.com/addvox7-voice-speech-amplifier.html
Vibration-Sensitive Adapters:
Chattervox Voice Amplifier Transdermal Neck Microphone:
http://www.harriscomm.com/chattervox-voice-amplifier-transdermal-neck-microphone-tm200.html
Sound Wave-Sensitive Options:
Chattervox Voice Amplifier Collar Microphone:
http://www.harriscomm.com/chattervox-voice-amplifier-collar-microphone.html