Everybody knows the constant whisper of air vents in hotel bathrooms or in restrooms of public places, a permanent sonic background to many modern buildings. The network of mechanized ventilation imposes a sound continuum on modern architecture that  provides an image of the rationalization of our interiour living conditions. Eric La Casa collects 30 recordings of such ventilation systems for his CD air.ratio that he made in different locations all over Paris. First the sound stamps are assembled in a quick sequence as a reference point, 2 seconds each location, then the 30 ventilation recordings are presented each for 2 min and finally followed by a minute of silence. While listening to the amplified humming of ventilation, certain psychoacoustic effects appear: one might hear voices or strange instruments in the modulated white noise of the air vents and think, those may be transmitted from other rooms in the building. At least I can easily imagine to start hearing ghosts if exposed to steady sounds like this. Eric remarks that this CD is intended to be an object without distinctive function. Neither scientific nor musical, this project could hold as an art installation (I envisage empty cold bathrooms with white tiles, in which the sounds are played) and by the same token as a minimalistic piece of sound art (just like the piece buildings by Francisco Lopez). Out at sirr records.