Acousmêtre - a kind of voice-character specific to cinema that derives mysterious powers from being heard and not seen. The disembodied voice seems to come from everywhere and therefore to have no clearly definded limits to its power.  

Acousmêtre depends for its effects on delaying the fusion of sound and image to the extreme, by suppling the sound - almost av voice - and witholding the image of the sound´s true source until nearly the very end of the film. Only then, when the audience has used its imagination to the fullest is the real identity of the sound revealed, almost always with a accompanying loss off imagined power. As long as we can´t see whom we attribute all-seeing power to the voice, but once inscribed in the visual field he loses his aura (as the wizard in the Wizard of Oz and HAL in 2001).  
   
  

(Edited excerpt: Michel Chion, Audio-Vision)  
  

Audio-Vision: Sound on Screen  is  available at Internet book stores as  Amazon books   Highly recommended
 

• The Voice in Cinema 
• David Lynch
• The Films of Jacques Tati 

• "Chion is a poet in theoretician's clothing" 

- Claudia Gorbman writes about Michel Chion

• Book Review: Michel Chion, Audio-Vision (Escom Newsletters)   

- by Nicola Phillips Faculty of Music, University of Cambridge

• Michel Chion´s Terminology

Film Sound Design    www.filmsound.org       Oxford University: "...an excellent collection of resources and links.."