Busy tone recognition device

The utility model discloses a busy tone recognition device, which is installed in a stored program control exchange and comprises an acquisition module connected to the stored program control exchange; the volume amplification and shaping module is connected to the acquisition module; the MCU frequency discrimination module is connected to the volume amplification and shaping module; the output module is connected to the MCU frequency discrimination module and the stored program control exchange; according to the busy tone recognition device provided by the embodiment of the utility model, the acquisition module is used for acquiring the voice signal in the call state in the switch telephone network and sending the voice signal to the volume amplification and shaping module, and the volume amplification and shaping module is used for amplifying and shaping the voice signal to obtain the square-waveform voice signal; the MCU frequency discrimination module discriminates the processed square waveform voice sign