This sound has been broadcast from the radio station, UVB-76 since 1987. It is not a loop (occasionally talking can be heard in the background) and has only been interrupted three times, once in 1997, once in 2002 and once in 2006. In each case, a Russian voice read off a list of names. On February 20, 2010, music could be heard interrupting the tone for about 4-5 seconds. http://en.wikipedia.org/wiki/UVB-76
Posted on Tuesday, 2 March 2010