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