H04M1/00—Substation equipment, e.g. for use by subscribers
H04M1/64—Automatic arrangements for answering calls; Automatic arrangements for recording messages for absent subscribers; Arrangements for recording conversations
H04M1/65—Recording arrangements for recording a message from the calling party
H04M1/654—Telephone line monitoring circuits therefor, e.g. ring detectors
H04M1/6545—Telephone line monitoring circuits therefor, e.g. ring detectors mechanically actuating hook switch, e.g. lifting handset