{HEAD ~ The apparatus} 8, wherein said alerting means includes means for transmitting {TAIL ~ a distinguishable audio signal} 
{ HEAD ~ The apparatus } 8 , wherein said alerting means includes means for transmitting { TAIL ~ a distinguishable audio signal }
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL