After detecting the residual noise, the second input transducer outputs {TAIL ~ a signal} to the electrical circuitry in {HEAD ~ the control unit} of the invention so that an opposing sound wave 180° out of phase with the residual noise will be input into the ear canal cavity by the output transducer 
After detecting the residual noise , the second input transducer outputs { TAIL ~ a signal } to the electrical circuitry in { HEAD ~ the control unit } of the invention so that an opposing sound wave 180 ° out of phase with the residual noise will be input into the ear canal cavity by the output transducer
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH