Static power pulse
According to the Eleventh Doctor, a static power pulse was as "characteristic as an audio signature" to the Daleks. Amy Pond likened it to a giant heartbeat. (COMIC: The Only Good Dalek)
It's the sound that means death and destruction... the sound that means death and fear... the sound that means the Daleks are coming.
The distinctive sound was heard within most Dalek bases, including the Dalek City on Skaro at the time of the Thal-Dalek battle and the Hybrid Incident, (TV: The Daleks, The Magician's Apprentice/The Witch's Familiar) the Cult of Skaro's Transgenic Laboratory (TV: Daleks in Manhattan/Evolution of the Daleks) and Dalek spaceships, (TV: Into the Dalek, The Time of the Doctor) including the Dalek Flagship in 200,100 (TV: Bad Wolf/The Parting of the Ways) and in 2106. (GAME: The Eternity Clock)
Whilst being taken to a Dalek confinement zone on Heaven, Jason Kane said that "that noise" was "actually very calming. Ambient." (AUDIO: Death and the Daleks)
A static power pulse sounded when a Dalek saucer's Progenitor Chamber created the New Dalek Paradigm. (TV: Victory of the Daleks)
Within the Old Skaro Emperor's psychoscape in the Dalek Dome, the Fourteenth Doctor followed the familiar "badum badum" sound to what he knew to be the Dalek control centre, where the Emperor resided. (COMIC: Liberation of the Daleks [+]Loading...["Liberation of the Daleks (comic story)"])
Behind the scenes
The sound can be heard in a ship amongst the Dalek War Fleet in the "Next Time" trailer for The Vanquishers, but was unheard in the final cut of the episode itself.
