Sound Atmosphere After the Wildfires

 

The silhouette of a crow standing on the remnants of a house in Altadena. Photo by Myriam Mahiques, March 2025.

 Each neighborhood and city has a unique sound configuration, depending on the sources.

In architecture, sound is studied as acoustic design and it is focused on concert halls and theaters.  But the sound of the environment is usually not considered.

During the wildfires and immediately after, the loudest sounds will be related to firefighters’ effort. The desperation in human voices, the evacuation orders, will open the path to sirens, roars of cars and then bulldozers clearing debris.

Those are the immediate sounds that will be replaced by a long period of silence.  I have been walking amidst the ruins of Altadena, and the lack of urban sound, except for the crows and distant roosters,  is truly impressive. My perception of the place was affected, it reminded me somehow of my visits to the countryside, but without the birds’ songs.

 

A single bird in the distance amidst the ruins of a house in Altadena. Photo by Myriam Mahiques, March 2025.

 Wildfires can dramatically alter the landscape and the soundscape.

In California, a group of researchers with data collected since 2009, mapped the sounds of the Hermit Warbler and analyzed the impacts caused by forest fires on the birds’ songs. They found that after the massive effect of bird dispersion, other individuals from different groups come to inhabit the affected areas, provoking a diversity of sounds which they call “introduction of new dialects”, in other words a Babel of bird songs.

Environmental sound can generate spatial engagement and provoke different reactions in humans depending on the context. The place can be “felt” in communion and this feeling will trigger memories:

“Sound as a concept invites us into the materiality of things, not to deny the visual but to augment how we might see; and it transgresses the boundaries between the object, the thing looked at, and the space and context of its appreciation, introducing a sense of simultaneity instead of pre-existence…” (Salome Voegelin. The Political Possibility of Sound. 2019).

 In “The End of Nature,” American environmentalist Bill McKibben states that the idea of nature can go extinct: “We spoiled and polluted parts of that nature, inflicted environmental “damage” (....) the meaning of the wind, the sun, the rain -of nature- has already changed.”

To understand what is ending, he proposes to look at the past. He cites one of the first America’s professional naturalists, William Bartram, whose  travel report in America recounts the beauty of different plants and animals species in a wild fresh land.

But before Bartram, and coming back to the soundscape, it is interesting to recall the work of the German Jesuit monk Athanasius Kircher (1602-1680), author of the first acoustics treatise in the West, Phonurgia Nova (1673), published in the second half of the 17th century. Kircher designed a sounding city through acoustic experiments, for example, taking distances to represent the echoes based on a site’s topography. The echo was of common knowledge due to Ovid’s myth of the nymph Echo.

Phonurgia Nova tried to represent the sound ambiance of a place in times where sound and acoustics were specifically applied to the creation of instruments; the book was related to the world of the living, to the sounds of the universe, of nature (wind, echo, water) where humans walk alongside the divine celebrating the wonders of our planet. It did not align with science but to religious cosmogony. That was an anthropological point of view opposed to the Greeks’ who conceived nature as an immutable order that humans could not infringe.

Kircher wrote about different subjects, like astronomy, optics, geology, music, magnetism, alchemy, acoustics, etc. Though his writings were not accurate on explanations of physical phenomena, he was a precursor of multidisciplinarity.

Experiments with echoes. From Phonurgia Nova.

Man, music and landscape. From Phonurgia Nova.

Nowadays, far beyond our own perception of soundscape after a wildfire, we can rely on scientific works that have measured it. In “Changes on soundscapes reveal impacts of wildfires in the fauna of a Brazilian savanna” researchers M.H.L. Duarte et al explained how they used an ecoacoustics approach to assess fauna responses and recovery after wildfire in a Brazilian savanna.  Six passive acoustic monitoring devices were used to record soundscapes before and after a wildfire at burned and unburned sites 24 hours a day, from September 2012 to September 2013.

They concluded that wildfire altered biophonic activity and soniferous species richness, being insects the most affected animal group; biophonic activity and soniferous species richness tended to recover one year after the fire.

Comparative pictures. From “Changes on soundscapes reveal impacts of wildfires in the fauna of a Brazilian savanna”.

“The lack of studies on fire effects on fauna is probably a consequence of the difficulty to conduct large-scale controlled experiments to reproduce fire impacts due to the obvious risks of fire spreading outside the experimental areas and the ethical concerns for this elective disturbance in such a fragile system (...) As an innovative and alternative approach, ecoacoustics has recently proven to be effective to access and interpret changes in animal communities in face of anthropogenic disturbances” (M.H.L. Duarte et al, 2021).

 The work of soundscape ecologist Bernie Krause is even more important since he began recording the sounds of the natural world in 1968. He lost his house “Wild Sanctuary” in the North Bay Fires of October 2017, together with his recordings, but luckily, and due to the lack of the current government’s support to science, he backed them all up six months before.

Krause is the author of The Great Animal Orchestra among other books. His “niche hypothesis” called attention to the role that nature sounds has in healthy ecosystems.

The effect of global warming is expressed in the natural soundscape. Krause came back to the places he had been recording sounds before and he showed the comparative recordings; the silence is evident in recent years. He compares this outcome with our voices: when we are sick, they are absolutely changed. The birds are still there, but they are not singing.

 

Soundscape ecologists Bernie Krause on St Vincent Beach. Photograph by Tim Chapman. Shared from the Guardian’s article “The sound ecologist capturing a disappearing world: ‘70% of habitats I recorded are gone”.

I highly recommend a New Yorker’s video on YouTube “How Soundscapes Change After A Fire. The Last of the Nightingales” which is not only beautiful in its black and white aesthetics, but also gives us the opportunity to listen to Bernie Krause and some of his recordings.

“-So if you wanna know how to learn to feel good and relaxed and being part of the living world around you, get involved in listening to it because it’s fabulous.” Bernie Krause, 2025.

                                  

 Sugarloaf Ridge State Park, eco-acoustic May 21st, 2000.

Sugarloaf Ridge State Park, eco-acoustic April 4th, 2008.The same calibrations are used in both days. See the differences in sounds. This one is more silent. 

Birds can instinctively fly away from a wildfire, “direct mortality is not a big concern,” says U.S. Forest Service research biologist Vicki Saab, quoted on Wild Birds Unlimited, but how do they survive in devastated areas after months?. Their food will be gone, the streams will be dry and full of ashes. We could approach and interact with nature in certain ways, for example providing safe feeding stations in backyards (out of reach of dogs, cats), shadow areas and water. 

Communities can be engaged in the research about how wildfires smoke along the U.S. West Coast  impacts birds by participating in the Project Phoenix, an initiative created by UCLA and the Natural History Museum of Los Angeles County. The goal is developing strategies to help birds cope with wildfires, air pollution and climate change.

https://www.project-phoenix-investigating-bird-responses-to-smoke.org/ 

Picture from Project Phoenix. 

Music from the environment is a complex phenomenon and we should give it a thought during the design process. The interaction between humans and animals is relevant due to the positive emotional and healing effects after trauma; this is one of the aspects of Biophilic design. 

Project management teams should include the collaboration of architects, musicians, acousticians, landscape designers, biologists.

In the words of Juhani Pallasmaa, sound provides a temporal continuum and architecture is the art of petrified silence. “Site isolates, whereas sound incorporates; vision is directional, whereas sound is omni-directional. The sense of sight implies exteriority, but sound creates an experience of interiority. (Pallasmaa, 2005) 

References:

 . Furnas, B.J., Landers, R.H., & Bowie, R.C. (2020). Wildfires and mass effects of dispersal disrupt the local uniformity of type I songs of hermit warblers in California. The Auk, 137(3).

. Kircher, Athanasius. Phonurgia Nova (1673).

. McKibben, Bill. The End of Nature. New York. 2003.

. M.H.L. Duarte et al. Changes on soundscapes reveal impacts of wildfires in the fauna of a Brazilian savanna.  In Science of Total Environment. Volume 769, 15 May 2021

. Regnault, Cecile. The Instrumentarium of Kircher. Premises of a Universal Phonurgy. In The Sound of Architecture. Acoustic Atmospheres in Place. Leuven University Press. P. 179-191. 2022 EPDF edition 2025.

. The New Yorker. “How Soundscapes Change After a Fire. The Last of the Nightingales”

https://www.youtube.com/watch?v=w-0IzU1EDdk

NOTE: this article is also published on AIA Los Angeles blog. This post has been completed with Cecile Renault's reference, which is missing from the AIA post.

https://www.aialosangeles.org/news/news-and-blogs/

Landscape and defensible space

 

A sketch of the Defensible Zones. From Fire Safe Marin

 After the deadly wildfires of January 2025, the high fire risk zones in California will be subjected to a new requirement which bans all combustible materials within 5 ft of residences, in a “Zone 0” . The goal is to create a defensible space around homes that slows the fast path of the wildfires.

The City Council of San Francisco Bay Area has already voted for it, and next year one thousand homes in Berkeley Hills will be under this regulation.

Though it will be difficult for residents to comply with it, California is in the process of adopting the Zone Zero requirements.

The executive order issued by CA Governor Newsom, published on February 6th 2025, does the following:

. Directs the State Board of Forestry to accelerate its work to adopt regulations known as “Zone 0”, which will require an ember-resistant zone within 5 feet of structures located in the highest fire severity zones in the state.

. Tasks the Office of the State Fire Marshal with releasing updated Fire Hazard Severity Zone maps for areas under local government responsibility, adding 1.4 million new acres of land into the two higher tiers of fire severity, which will update building and local planning requirements for these communities statewide. *

. Requires the Department of Forestry and Fire Protection (CAL FIRE) and the Governor’s Office of Emergency Services (CAl OES) to work with local, federal and tribal partners on improvements to the Federal resource ordering system for wildfire response.

 Special attention deserves the inclusion of tribal partners, since there is a historical record for disagreeing  with the Forest Service fire suppression policies and the indigenous people’s fire practices, since they have always relied on the use of fire to manage the landscape for food and cultural material needs. “Like the Spanish before them, federal foresters had determined that because fire was the enemy of productive and profitable forest management, those who advocated its use -like fire itself- must be suppressed. As Karl Marie Norgaard notes, “The exclusion of fire from the landscape has led to a dramatic reduction in the quality and quantity of traditional foods, negatively affected spiritual practices, threatened cultural identity, and infringed upon political sovereignty.” (Miller, 2024)

 Landscape architects have proved that the Zone 0 policy is not totally correct. On April 9th 2025, I have assisted to a Webinar about Landscape - Defensible Space where architect Clark Stevens (sustainable land use planner) has shown that many houses in green corridors of Los Angeles were saved:

Christmas Tree lane is the diagonal in the second map. The conifers corridor did not transmit fire. Basically, per his explanation, more gardens mean less houses burnt.

 

The defensible space focuses on how to reduce direct flame contact. But there are different approaches that we should consider as well, like planting high moisture plants, using fire rated mulch or non combustible ground cover.

The Home Protection Zone should be designed to promote fire-wise landscaping and water conservation. The landscape professionals’ recommendation is to begin with a minimum planting zone of native species to medium density as we move outward the house.

Use more irrigation on Zones 0 and 1. Decrease the irrigation when the distance increases. It is  not about the use of water but the retention, like planting cactus or having swimming pools.

The following sketch, from the Webinar, exemplifies the best transition between defensible zones:

References:

Cut back your roses? Berkeley sets new rules for its most wildfire-prone areas. April 16th, 2025.

Miller, Char (editor). Burn Scars. A Documentary History of Fire Suppression, from Colonial Origins to the Resurgence of Cultural Burning. Oregon State University Press. 2024.

*An interactive map can be seen on pyrecast.org where we can select fuels, weather, risk and active fires. It allows all users, including homeowners and developers, to evaluate the fire hazard conditions of every lot in the USA.

NOTE: this post is also published on AIA Los Angeles blog:

https://www.aialosangeles.org/news/news-and-blogs/