Low cost telephone services acoustic dialling access having stored DTMF code dialling sequence acoustically reproduced and external face placed secure dialling code reproduced and peelable layer covered.

摘要

The portable acoustic number dialler stores a pre-set dialling sequence and generates DTMF codes corresponding to this sequence. A sound transducer transmits acoustic codes. An external face (2) has a message (6) which includes secure information reproducing the dialling sequence stored. The message is masked by a peelable opaque layer.