PURPOSE: To prevent a noisy incoming tone by outputting the incoming tone after lapse of a preset time after the detection of the incoming signal to install other telephone set at a location where a received call is not normally replied.
CONSTITUTION: When an incoming call signal detection section 11 detects an incoming call signal from a telephone line 16, the incoming call signal detection section 11 drives an incoming call signal transmission timer section 12, a timer built therein starts its operation. The timer of the incoming call signal transmission timer section 12 is operated consecutively for a preset time by a timer setting section 13 and the section 12 drives an incoming call signal tone generating section 14. Then the section 14 generates an incoming call tone and an incoming call tone output section 15 outputs an incoming call tone audibly. On the other hand, when the incoming call signal from the telephone line 16 is stopped or no incoming call signal exists, the incoming call signal detection section 11 does not generate the incoming call tone to the incoming call signal tone generating section 14. Thus, when another telephone set is placed at a location where a received call is not normally replied, a noisy incoming call tone is prevented.