A device for performing {HEAD ~ electroacoustic functions} including noise cancellation, communication interface, and {TAIL ~ headphone functions} 
including
A device for performing { HEAD ~ electroacoustic functions } including noise cancellation , communication interface , and { TAIL ~ headphone functions }
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL