Absolutely Bizarre overview of what the telephone system sounded like back in the 1970’s and 1980’s. Very very little of the modern digital telephone sounds you hear when using your land line make the same sounds today as they did back then. A fascinating record that would be useful for sound recordings. 

If nothing else, you have to hear how smooth the announcer’s voice is who presents all these strange sounds, if he’s not a radio personality, I’d be surprised.