An intercom exchange is connected to multiple terminals, and includes multiple communication paths, a digital switch circuit for switching connections between the terminals and the communication paths, and a CPU that controls the DSPs and the switch circuit. The CPU performs control for preferentially allocating a communication path to the first terminal, and the allocated DSP determines whether a sound from the first terminal that has been received as input via the switch circuit is an abnormal sound. Upon determining that the sound is an abnormal sound, the allocated DSP notifies the CPU, and upon receiving the notification, the CPU determines an alert destination based on the notification and performs alert processing for sending an alert to the alert destination.