Sound Walls 1

Sound Walls will be a set of recurring posts which question the fundamental assumptions of how to design for the sonic environment.  A 'sound wall' is typically referred to as a piece of infrastructure which serves to block or attenuate the transmission of sound.  This series I am calling Sound Walls will reconsider the sound wall as literally "a wall of sound" wherein sound is also a construction material.  We may build walls to control the transmission of sound, but we may also build walls out of sound alone.  

I will use this series to document a set of ideas and projects which take us from the sound wall as a necessary evil to exposing it as a fertile terrain for design exploration.

Sound walls: what do we think about them?  Do we think about them at all?  These highway barriers are dull; they are often made of concrete and hardly merit our prolonged attention.  They are often poorly camouflaged, imprinted with annoying patterns which attempt to give some kind of character to a neighborhood you blast by on the freeway.  Street artists and homeowners seem to be the only ones who appreciate them, and even then they are appreciated quantitatively: for the homeowner, attenuation of freeway noise, and for those with a can of spray paint, a large, flat surface in public view.  Seldom is a sound wall thought of as a universally desirable thing.

Architects have in a few cases been able to embed a 'something else' into the functionality of this infrastructure.  Jean Nouvel designed the Red Kilometer, a science and technology park outside of Milan.

[image: Jean Nouvel's Red Kilometer via Abitare]

The client desired a sound barrier from the adjacent expressway and Nouvel turned that into the concept for the masterplan.  There is certainly no attempt at camouflage here. An architectural adage goes: If you can't make it beautiful, make it big.  If you can't make it big, make it red.  Or, if you're Jean Nouvel, you can do both.

[image: Jean Nouvel's Red Kilometer via Abitare]

[image: Jean Nouvel's Red Kilometer via Abitare]

The Red Kilometer enjoys an object relationship with its surroundings.  While the contrast is remarkable, this is not a practice that would work for the majority of sound walls, especially in inner cities.  Would the residents on the opposite side of these massive red walls appreciate the attention to this barrier?  Would drivers be inclined to drive faster along a sleek red strip?  

[image: Jean Nouvel's Red Kilometer via Abitare]

Given that Nouvel installed numbers for parking spots that recall the race track and lighting which gives the space in front of the wall the appearance of an airport runway, I think speed over tranquility is indeed the desired performance of this sound wall.

So if the Red Kilometer is not to be a typological response to sound walls, what could be?  Two recent articles have prompted in me a desire to revisit the typology of sound walls.

The first comes from the Washington Post where we learn about plans to build a sound wall along the Dulles Toll Road.  The problem of highway noise is nothing new for the neighboring communities:

Shouse Village, a Vienna community of 260 houses, has lobbied federal and local officials for sound walls, but to no avail.  A batch of trees separates Shouse Village from the toll road. But when the leaves fall, the highway noise gets louder, said Sue Rosenberg, vice president of the homeowners association. 
"I can hear the noise, and I don't live anywhere near" the tree line, she said.
So a community with a bit of economic leverage can petition to get a sound wall built (nothing new here), but my attention hangs on that bit in the middle about "when the leaves fall, the highway noise gets louder".  Fantastic!  We don't need a new sound wall, we just need to invent a seasonal sound wall, one which goes up as the leaves fall down.  We can imagine all sorts of possibilities, deploying light materials which simulate the density of trees, perhaps even hanging from the trees themselves.  We could get Cristo to design sound walls, too.

The second article comes from the San Francisco Chronicle.  In this case a temporary sound wall is drawing the complaints of its neighbors who sued over construction noise to get it in the first place.  Caltrans, the agency responsible for the construction noise, is now bowing to public pressure and is prepared to plant a row of trees in order to screen the ugliness of the temporary wall.  It will eventually be replaced by an earthen berm when the Caldecott Tunnel opens in 2014.

[image: Michael Macor / The Chronicle]

The case of this barrier also makes me wonder about the sound walls erected in communities that lack a rich homeowners association capable of launching lawsuits over sound walls.  For the designer, the task is to produce sound walls which do not recall the oppressive forms of contemporary barriers on the US-Mexico border or in Israel-Palestine.  Like these other barriers, sound walls are messy things because they are so political--couched in lawsuits, never really wanted in the first place, and in my opinion, an out-dated response to sources of noise.

[image: wall dividing Israel and Palestine]

We should start re-thinking what a sound wall could be.  A big part of this task is to examine the source of 'noise' which gives rise to the need for sound walls.  Can we build fewer--or better--sound walls if we shift the perception of noise?  What if we could condition noise into something desirable?

I will leave off with a possible future for sound walls.  In Japan, they have been developing over the past decade sound walls with active noise cancelling.  Microphones record the sound of traffic and playback the sound out of phase to cancel it out, just like noise cancelling headphones.  This technology can reduce the height of wall that is needed.  Could we arrive at a moment where physical mass is not needed at all, and a sophisticated array of noise cancelling monitors could invisibly silence a freeway?

The intention of this series is not to propose ever more elaborate technologies to reduce the sound wall.  Rather, I am interested in shifting the perception of both sound walls and the sound they wish to block, and in so doing, bring some much needed attention from the design world to this subject.