Abstract: An analyzer for noise signals which are transmitted by a telephone pair in a telephone cable is connected to a digital transmission equalizer. A delimiting circuits delimits the binary stream generated by the threshold detector into data packets such that each stream is considered to be a unique packet as long as the stream does not comprise a predetermined number of zeros. At predetermined instants, writing is triggered into a random access data memory to store the contents of a schedule data register, of a storage register and of a frame unique word register. The time base also comprises an output connected to an incrementing input of an address counter and to an output connected to the zero reset input of storage register.