The unit may also have other pieces such as microphones and {TAIL ~ speakers} in order to allow communication in {HEAD ~ difficult circumstances} to be facilitated 
The unit may also have other pieces such as microphones and { TAIL ~ speakers } in order to allow communication in { HEAD ~ difficult circumstances } to be facilitated
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH