Device for detecting tones on telephone lines

A method of detecting on a pair of telephone line conductors the presence of a stuttered dial tone comprising:

• (a) connecting the pair of conductors with an off hook impedance in response to one or more events selected from the following group:
• (i) periodically where the periods are between one minute and 24 hours,
• (ii) within one hour after a use of the line, and
• (iii) within one hour after a ring;
• (b) detecting whether the stuttered dial tone is present on the line;
• and
• (c) indicating if the stuttered dial tone is detected on the line.

A device for connecting to a telephone line for indicating the presence of a message waiting signal on the line comprising:

• (a) line interface means for establishing communications on the line in response to one or more events selected from the following group:
• (i) periodically where the periods are between one second and 24 hours,
• (ii) within one hour after a use of the line, and
• (iii) within one hour after a ring;
• (b) detection means for sensing whether the message waiting signal is present on the line;
• and
• (c) indicator means, responsive to the detection means, for indicating whether the message waiting signal is present on the line.

A method of detecting on a telephone line the presence of a message waiting signal comprising:

• (a) establishing communication on the line in response to one or more events selected from the following group:
• (i) periodically where the periods are between one minute and 24 hours,
• (ii) within one hour after a use of the line, and
• (iii) within one hour after a ring;
• (b) detecting whether the message waiting signal is present on the line;
• and
• (c) indicating if the message waiting signal is detected on the line.