{TAIL ~ An audio speaker} is physically situated near the doorbell switch, for reproducing audio signals from the telephone line which are generated at {HEAD ~ the remote telephone} 
{ TAIL ~ An audio speaker } is physically situated near the doorbell switch , for reproducing audio signals from the telephone line which are generated at { HEAD ~ the remote telephone }
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD