Specifying sound here obviously suggests that spectacular power cannot be reduced to an optical model but is inseparable from a larger organization of perceptual consumption. Sound had of course been part of cinema in various additive forms from the beginning, but the introduction of sync sound trans- formed the nature of attention that was demanded of a viewer. Possibly it is a break that makes previous forms of cinema actually closer to the optical devices of the late nineteenth century.

The full coincidence of sound with image, of voice with figure, not only was a crucial new way of organizing space, time, and narrative, but it instituted a more commanding authority over the observer, enforcing a new kind of attention. A vivid sign of this shift can be seen in Fritz Lang's two Mabuse films. In Dr. Mabuse the Gambler, a 1924 silent film, the proto-fascist Mabuse exercises control through his gaze, with a hypnotic optical power; while in The Testament of Dr. Mabuse (1931) an incarnation of the same character dominates his underlings only through his voice, emanating from
behind a curtain (which, it turns out, conceals not a person, but recording technology and a loudspeaker).

Spectacle, Attention, Counter-Memory
by Jonathan Crary