Mystery and famous signals

The sounds people ask about most: what they are, where they come from, and how to hear them yourself.

• UVB-76 (The Buzzer)
  UVB-76 sounds like a harsh, low, foghorn-like buzz repeating about 25 times a minute, day…
• Numbers stations
  A numbers station sounds like a flat, often synthetic voice reading groups of digits on…
• The Woodpecker and OTH radar
  Over-the-horizon radar sounds like fast, harsh tapping or a rapid buzzing sweep across a…
• Time stations
  A time station sounds like a clock ticking once a second, with a longer beep at the top…
• Emergency alert tones
  A weather alert sounds like three short screeching bursts of data, then a long steady…
• ISS SSTV pictures
  Pictures from the space station sound like a fast, warbling whistle with a steady ticking…
• Weather satellite sounds
  A NOAA weather satellite sounded like a steady tick-tock, two ticks a second, over a…

Looking for a particular mode? See the signal guide.