Abstract: A generator of ringing signals at a subscriber station of a telecommunication system, designed to respond to electromechanically generated lower-frequency call signals of large amplitude as well as to electronically generated higher-frequency call signals of small amplitude emanating from a central office, comprises a signal identifier and a level discriminator connected in parallel to an incoming line. The signal identifier includes a local oscillator emitting a train of pulses at a cadence substantially higher than any call-signal frequency which, in the presence of an incoming signal, are fed to a pulse counter during alternate half-cycles of a square wave derived from that signal.