Abstract: This arrangement has an input (10) for receiving the information to be encoded in the form of fixed words comprising a number of bits, a first transcoding member (20) for applying said variable word to "n" outputs among n parallel outputs, a second transcoding member (22) for supplying from its output the indication of the length (n), and an accumulation member (30) for forming a first "modulo N" accumulated information and a second "modulo 2N" accumulated information, which are the result of operations performed on "n".

Abstract: An anti-Larsen circuit for a telephone station in which the listening channel comprises an automatic listening level control circuit, suitably of the type comprising a variable attenuator circuit, a pulse-width modulator and a threshold detector which supplies compression pulses. The transmission channel comprises a circuit for rendering the transmission channel operative or inoperative and also a control circuit. Actuation takes place above a sound-level threshold S.sub.1 and a de-activation below a sound-level threshold S.sub.2 which is smaller than S.sub.1.

Abstract: This arrangement comprises a controllable attenuation circuit of the voice signal received, a pulse-duration modulator which produces pulses the duration of which is modulated by the voice signal supplied by the controllable attenuation circuit, an overshoot detection circuit which produces from the modulated pulses a compression pulse each time it is detected that the amplitude of the modulated voice signal reaches a certain threshold, the compression signal produced by the said overshoot detection circuit being applied in the attenuation circuit to an integrating circuit which produces the attenuation control signal. The amplifier of the loudspeaker receives the modulated signal.