The second transducer lies in the plane of the input and output transducers of the parent application, but faces the ear canal cavity so that it detects {HEAD ~ the residual uncancelled noise} present inside {TAIL ~ the ear canal cavity} 
present inside
The second transducer lies in the plane of the input and output transducers of the parent application , but faces the ear canal cavity so that it detects { HEAD ~ the residual uncancelled noise } present inside { TAIL ~ the ear canal cavity }
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 HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL