As Het HEM has developed its program and identity during its first few years of being open, Het HEM has supported research by musicians and (sound) artists into the building’s unique architecture. This has led to interesting discoveries and long-term partnerships that we hope will continue to grow as our space changes - particularly during and after Het HEM’s renovation. We welcomed artists Pamela Jordan and Sergio González Cuervo to make use of Het HEM’s cavern-ous factory floor as they ask: what sounds are still echoing around in here?

As part of their collaborative project Re:Sounding, Sergio González Cuervo and Archaeology PhD candidate Pamela Jordan are analysing the acoustics of various historical buildings throughout The Netherlands. Architects, spatial designers and users often overlook the impact of acoustics and sound on the experience of a space – unless this is part of the building's primary function, like a concert hall. But sound plays a central role in how we physically and mentally experience and interact with a building, stirring up memories and awakening a sense of imagination. By studying the current sounds of a place, it is possible to retrace its acoustic history and get an idea of how the building has been used throughout different periods.

Throughout 2022, Jordan and Cuervo spent many hours at Het HEM, investigating its acoustics, making field recordings and developing a method to analyse the built environment and its history. This type of research is related to sonic archaeology. We interviewed them about their discoveries. (update 21 July 2023: find an extended version of this interview on The Couch)

HH: Can you tell us where your interest in sonic archaeology started?

Sergio González Cuervo: I studied sound engineering, so acoustics always played a role in my formal training. But mainly when I started to work on sound for film, I became aware of how acoustics define a space and our experience of it, and also how this can be used to tell a story. The implications of this became more palpable when I started working with Pam one and a half years ago.

Pamela Jordan: For me, it happened somewhat the other way around. I worked as an architect specializing in heritage, but I have always been interested in acoustics. The firm I worked for was commissioned to develop a mixed-use dormitory for the first school in the US for deaf and hearing -impaired students, Galludet University. The university team had developed a system of architectural design for those who don’t use hearing to orient themselves, centred on the concept of ‘deaf space’. Learning about this flipped my perception of architecture on its head, because suddenly all of the assumptions I had made throughout my education were inappropriate for a whole population of people. I started to think more broadly about sound in space, also from a heritage perspective. As sound is a means to orient and understand a space, can we then also do that in a historic sense? Can sound be an artefact in some way?

This interest became even more concrete when visiting the Berlin Wall Memorial at Bernauer Strasse, one of the most intact pieces of the former Berlin Wall. The western side is adjacent to a busy and cacophonous street – you almost forget the Wall is there. Walking to the other side into former East Berlin, a choreography of sonic cues starts to add up. It can be experienced like compression space between walls, the changing material under your feet from hard surface to gravel. When you enter the memorial, it’s silent in comparison. You look over the Wall to the West and you see people standing on a reconstructed watchtower. Suddenly you realize that the silence isn’t just calm, it’s a military instrument, an element of surveillance. Sound and silence communicate the meaning in these different spaces. I could get an understanding today of the historic relevance of these spaces by listening.

HH: What attracted you about Het HEM for your research?

PJ: I was part of the Shock Forest Group, the interdisciplinary research group which the com-poser Nicolás Jaar created as part of his Chapter 2WO at Het HEM in 2019, so I knew a lot about the heritage of the building. On the first day when I arrived, I walked through the top floor when it was empty, and I noticed this amazing echo. I just wanted to explore it.

SGC: We had never encountered an echo with such characteristics before. By doing acoustic tests like clapping and popping balloons we noticed something special in the reverberation of the space: sound would bounce back and forth several times against the walls of the long side of the building, creating an acoustic 'ping pong delay' naturally. In our explorations, we always take into account what was happening in the space in the past. We reconstruct sonic elements of that past while trying to find an acoustic signature that we also consider aesthetically unique: What was the position and the purpose of humans and machines on the factory floor of Het HEM? How did they interact with each other and with the architecture? How did they experience the sound of the building themselves? These are questions we took into account when deciding on the approach of our acoustics study of Het HEM, even if the ping pong delay we were so fascinated about was not necessarily related to the previous function of the factory.

PJ: Het HEM isn’t a building designed with acoustics in mind the way the Oude Kerk in Amster-dam is. However, even a space like an ammunition factory has acoustic meaning and function. What I find very interesting is that the sounds that we heard and recorded at Het HEM very much describe the construction of the building. How the walls, the columns and the windows are put together… It felt like we were listening to the architecture itself.

HH: What do you do exactly when you explore and record the acoustics of a building?

PJ: Each building requires a different sensitivity of listening. Het HEM is huge, so we need tools that are able to capture the full range of sounds in the space. We start by using quite basic tools, such as our own hands, but also more advanced recording equipment. The first things we do is walk around and clap to hear what the building is giving back to us. We use impact sounds, like clapping or exploding balloons, to see how the frequency bends, what special effects occur and what feedback we are getting. Then we need to figure out how we can record this. Sound isn’t static. It moves through the space, and we are moving through the space too, so we need to be very creative in finding ways to capture that.

SCG: We listen to the space from different angles and start to make connections. In the beginning we have a collection of sound elements that seem unrelated. We pay attention to how the sound in one spot is affected by the different rooms that conform the building and how they are connected to each other, their geometry, the materials they are built from, the objects inside... And make a relationship between that, the sound we perceive and the various stories that we dig up. We analyse and compare the recordings we make, trying to find a way to represent and document the attributes we find interesting in those acoustics, in such a way that we can recreate them afterwards in the sound studio.

PJ: The human dimension of sound is not often talked about when we talk about acoustics in a space. Sergio and I always approach sound from the perspective that a human will experience it. We don’t just use instruments to document something abstract, because when are talking about historic value, it’s always related to a person listening to and hearing the sound.

HH: What did you learn about the previous function of the building as an ammunition factory?

PJ: We asked ourselves: what are the relationships between spaces across the building? What was the effect of shooting in the basement range for the people working in other areas of the building? Sound is a messenger on this terrain, in a way that is different from other buildings.

Silence only exists in relation to sound, so the silence in this building and on the surrounding terrain is always connected to the absence of explosions and impact of destruction in the case something went wrong. The fact that ammunition was created here and tested here, always brought the potential of explosions to the forefront. Het HEM presents these potent questions that I would not have thought about if I hadn’t approached the location through its sounds. We thought of re-enacting this, to unload a gun in the shooting range for example to get a better sense of this latent presence of destruction.

HH: So what outcome do you expect of this process?

SC: We find it very exciting to discover an acoustic quality that is at the same time interesting sounding, representative of the history of the space and somehow unexpected considering what we see. After spending sometime doing our tests, that is more or less what normally happens. As we are talking now, I notice that Orpheu’s voice is dry, as if he is in a very dry sounding room. And Rieke’s voice is echoing as if she is in a very open space. These acoustics give us infor-mation about size, geometry, materials, without much visual input. Information that determines the architecture of a space, which we receive unconsciously. Our project tries to take this information out of the unconscious experience and do something creative with it.

PJ: Even if we train our ears to listen, we still have to come up with language of how to communicate these sounds to each other and to a broader audience. The research we are doing at Het HEM and at Oude Kerk is about that. Very few people can listen to an impact sound – like a clap or an explosion - and gain information from that, because we haven’t trained our ears to hear the differences.

SCG: These days we are exposed to a lot of carefully designed visual information. Therefore an average person is visually quite experienced, in my opinion, but that is not necessarily the case with sound. However, I believe that we actually can 'visualise' through sound, and also that we already are more capable than we think. We have learnt a lot about it unconsciously through our everyday life. Try to imagine: how does a person speaking in a church sound like, compared to your bedroom, compared to your bathroom? You can recognise each of these spaces with your eyes closed just by the sound.

PJ: There is a test that I often ask my students to do. Sit in a room with closed eyes. After a moment, ask whether the door is open or closed. Just by paying attention to the acoustics, you can hear the position of the static door. Those of us who are able to use their hearing use this knowledge all the time. We are highly sensitive already, and what Sergio and I do is to amplify that sensitivity by using tools so that we can turn those observations into information.

HH: In what way can your research be of interest to other artists, researchers, performers, de-signers or composers?

SCG: We believe there is a great value in sound preservation. The original functionality of a building like Het HEM no longer exists. The acoustics of the building might change or disappear over time. We document the acoustics of Het HEM in a way that can be re-enacted. In a way, it is like we make a sound picture. This can be valuable for architects in the future, but also in the world of media, or anywhere where you need to 'reconstruct' a space through sound. During our residency here, we took some of the acoustic signatures of Het HEM, so we could partially recreate the sound of the factory when it was still active.

PJ: The One Square Inch Project is an initiative by Gordon Hempton to raise awareness of the impact of human-produced sound worldwide. By his analysis, there are no spots on Earth free of human noise impacts. The last time I checked, he mentioned there were only 12 in the US with at least 15 consecutive minutes without human sounds. With our research, we wish to raise a similar awareness about our acoustic environment and the impact that it has on us and on various non-humans. At the same time, we are also developing a methodology of how to study and explore sound in our built environment, how to approach sites from their acoustic angle, how to draw up their acoustic signature and what to do with this material.