‘Annoying’ Noise Potential and Adaptive Shape

 

We have already identified the ‘potential’ for noise at the selected site, given that is basically an open void to a multi-lane interstate roadway.  I do not usually think that noise is a particularly insightful site force, simply because urban environments are noisy by nature (this kind of sight analysis usually leads to diagrams of the obvious).  I hope this vein of analysis can be a bit more instructive (you can let me know if it is not).

Hoping to engage (and/or mitigate) the noise ‘potential’ at the proposed site, I have tried to model the behavior of noise in and around the site: first, with existing site conditions and then with a proposed massing on top of the site.  Some computer modeling demonstrated that the main source of noise at the site comes from the several lanes of traffic below the void that I hope to span with the new library as opposed to the surface traffic along Massachusetts Ave. and Boylston St.  More specifically, it is the persistent echo and reverberation of sound emitted from the sub-surface roadway that shapes the sound environment most dramatically.  

The attached animations model a theoretical sound source, in this case an 85 dB, 1200 Hz multi-directional source representative of ‘heavy traffic’ as defined by the US Department of Energy (which is coincidentally within the range of what the DOE defines as ‘annoying’ sound levels).  A comparison of these analyses tells me two things particularly: 1) The shape of the site, once filled with direct and reflected sound, affects how that sound is attenuated over time and this shape has a tendency to hold sound like a vessel and 2) any proposed building proposed at the site will not only have to deal with dramatic noise characteristics but it also has the potential to shape how this sound is transmitted to the streetscape.  I see my proposed library as a layer of refuge within layers of environmental noise; the goal will be to shape the moments where these environments can interact.