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 Eleventh Doctor.

The distinctive sound was heard within most Dalek bases, including the Dalek City on Skaro, (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: Victory of the Daleks, Into the Dalek) including the Dalek Flagship. (TV: Bad Wolf/The Parting of the Ways)

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.