In the case that {HEAD ~ the sound processor} is connected to {TAIL ~ a plurality} of common buses, the bus interface means is also required for each of the common buses 
is connected to
In the case that { HEAD ~ the sound processor } is connected to { TAIL ~ a plurality } of common buses , the bus interface means is also required for each of the common buses
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH