Stairwells and Reflections: potential site #3

GUND HALL north stair @ Harvard GSD, Cambridge, MA

The stairwell (pictured above) is a particularly reverberant space which is immediately noticeable when you begin to move through it.  The five-story space is continuous from the first floor to the fifth floor ceiling, and is constructed of thick concrete walls so that all exposed surfaces are hard and reflective.  Subsequently, any signal or sound that is produced within the space lingers for several seconds due to reflections off all the surrounding hard surfaces and the extensive vertical geometry of the space.  The clip below demonstrates this phenomena.  I recorded myself clapping on the top floor of the stairwell.  Take a listen: You can clearly hear the reflections of my clap for several seconds after the initial impact.  In a space with more absorptive surfaces and smaller geometry, the experience would not be nearly the same.  Try clapping in the room you're sitting in now for comparison.

Egress stairs, which are required enclosures in most buildings in case of fire, are usually unused, un-inhabited and forgotten spaces in buildings, but because of code requirements dictating material etc. have distinct acoustical qualities.  As such, I am interested in their unique situation within the realm of architecture and acoustics.  In addition to reflections, I am also fascinated by the ambient sound of these spaces.  Depending on adjacent program and/or machinery and air circulation within the structure, these stairwell spaces create sound environments that are far from uniform across their vertical section. 

The following clip is created by alternating segments of recorded sound from various levels within the stairwell. The piece begins at the highest accessible level, the 5th floor. With duration of approximately 15 seconds, one’s ears become accustomed to the sound. It soon can be considered background noise. Suddenly, there is an abrupt change in the sound. Using a “jump cut”, the second segment is recorded on the 1st floor. It is higher and sharper. Soon, however, our ears become accustomed to this level’s unique hum, and the sound becomes a baseline once again. The successive segments are taken at the landing between the 4th and 5th floor, next at the landing between the 1st and 2nd floor, then the 4th floor, then the 2nd floor and so on, until the sequence ends at the 3rd floor.  

It is only when one stratum is directly compared to another that a difference is recognized and distance traveled can be appreciated. Through the displacement of each level’s ambient sound, it is revealed that there are actually distinct differences between the sound at varying levels within the same space.

I would be interested in conducting a comprehensive survey of the acoustics of these spaces. Each stairwell, though limited by code requirements, is also shaped by the specific conditions of the building they are a part of. This endeavor would be an experiment regarding the auditory perception of our surroundings. Are our ears constantly calibrating to our environment? At what point to they become aware of the inherent sound qualities of a specific location within a space?