, said his mother pioneered the system in Utah in 1978 to help his two hearing-impaired brothers at school. Since then the devices have been installed in some 75,000 classrooms from...

a small infrared wireless microphone that transmits their voice(s) to a speaker system evenly distributed throughout the classroom, typically in the ceiling. Using this device...

infrared wireless microphone that transmits their voice(s) to a speaker system evenly distributed throughout the classroom, typically in the ceiling. Using this device, teachers...

infrared wireless microphone that transmits their voice(s) to a speaker system evenly distributed throughout the classroom, typically in the ceiling. Using this device, teachers speak... at school. Since then the devices have been installed in some 75,000 classrooms from California to Florida, and Ohio is requiring them in every new school, Anderson said. Studies have... that transmits their voice(s) to a speaker system evenly distributed throughout the classroom, typically in the ceiling. Using this device, teachers speak in a normal one-on-one voice...