{TAIL ~ This invention} relates to electroacoustic devices for performing noise cancellation, communication interfacing, sound filtering, and headphone functions for {HEAD ~ the human ear} 
{ TAIL ~ This invention } relates to electroacoustic devices for performing noise cancellation , communication interfacing , sound filtering , and headphone functions for { HEAD ~ the human ear }
TAIL TAIL TAIL TAIL TAIL TAIL 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