From Bloxvox’s Voice-Dampening Device Gives Users Privacy During Calls:

Bloxvox inventor Greg Umhoefer demonstrates device
Bloxvox inventor Greg Umhoefer demonstrates device

Bloxvox, which fits over the mouth and allows users to muffle their voices when they’re talking on the phone, is sold by a Milwaukee-based startup of the same name. Image courtesy of Greg Umhoefer.