Lets go back to the orriginal point of the first post on this. It sounds to me like a Signal Mainter was testing the detector. I have been hearing these detectors now for over 27 years now and have never heard a train get that many readings, unless the Detector itself was messed up and when it happens, it is an earful. Signal Maintainers are required to do tests on these devices on a regular basis and will make them give as many readings as what the 1st poster described above. Some maintainers will actually do it on the road channel, some will put the radio on a different channel momentairily for these tests, and some will even unplug the audio cable leading to the radio so it doesn't transmit during their tests at all. It is a requirement that the Maintainer make the Detector say all it can say to insure it is working properly.
As far as the old SP Voice, I had heard that it was the voice of an SP Office Employee, but I never could confirm it and if so, never got a name of any kind. Right after this voice came into being in the winter of 1985, a member of the Glendale Model Railroad Club came up with the name "Ice Box Mary", although I agree with most, her voice was not icy cold by any means. In fact the modern Female Voice, found mostly on the UP is a product of Southern Tech./Industries and I do refer to it as "Ice Box Mary". I don't like the sound of it either, never did.