Sahar Asadollahi Asl Zarkhah (TU Delft & Erasmus MC) spends her days listening to cities. As one of the researchers behind the Resilient Delta initiative’s NOISELAB, she studies how sound shapes everyday life in a noisy port city like Rotterdam. Beyond measuring decibels, she is interested in how people experience urban sounds and how those experiences affect health, wellbeing and equality.

Along Rotterdam’s waterfronts, these questions are never abstract. A passing water taxi, the low constant presence of the port, the rhythmic sounds of construction across the city. For some residents, these sounds are familiar and grounding. For others, they disrupt sleep, concentration and rest. The difference, Asadollahi Asl Zarkhah says, is not only acoustic.

“Noise is often understood as a matter of decibels,” she says. “But sound is a lot more profound than that. It’s actually a huge part of how a city’s inhabitants live, sleep and interact with their surroundings.”

Listening beyond measurements

Asadollahi Asl Zarkhah’s academic background is rooted in the study of public space and community resilience. During her doctoral research, she spent long periods in Katendrecht, examining how streets, parks and waterfronts function in neighborhood life. Sound was not her initial focus, but it quickly emerged as a powerful influence.

“In my earlier work, we worked with sensory experience more broadly,” she explains. “Sound stood out, because it’s invisible. People rarely talk about it, unless it becomes a problem. And yet it affects them all the time.”

Sounds of Katendrecht

This led to Sounds of Katendrecht, a research and exhibition project that invited residents to map the sounds of their neighborhood using stories, colors and simple descriptions. What emerged was a layered picture of the neighborhood, shaped by the interplay between recorded sounds and lived experiences.

Long-term residents often described the sounds of ships and water traffic as part of the area’s identity. Newer residents were more likely to experience those same sounds as disturbance. “People hear the same thing,” Asadollahi Asl Zarkhah says. “But they do not experience it in the same way. Memory matters, belonging matters. Sound has personal and social aspects.”

NOISELAB

She now co-leads the Resilient Delta initiative’s NOISELAB, a collaborative initiative that brings together researchers from TU Delft, Erasmus University, Erasmus Medical Center and the Municipality of Rotterdam. The aim is to rethink how noise is understood and addressed in port city environments.

In pilot areas such as Charlois, the team combines sound measurements with resident input to explore how acoustic environments are experienced in relation to their spatial context. Measurements are used to identify dominant sound sources and patterns, while residents contribute insights into how sound is perceived in everyday life. In parallel, the built environment is analyzed across multiple scales, from urban layout and functional distribution to street profiles and building morphology, to understand how spatial configurations influence soundscapes.

As the research shows, design and spatial context play a key role in shaping how sound is experienced, including aspects such as building orientation, the presence of quieter façades, and access to more sheltered or calm spaces.

Noise as a health risk

When urban noise becomes a problem, it’s usually discussed in terms of nuisance. But research shows its effects go much deeper. Environmental noise is recognized as the second most significant environmental stressor on human health, after air pollution. “What changed my own thinking was working with medical researchers,” Asadollahi Asl Zarkhah says. “Even when people feel they have adapted to a sound, the body may still be reacting. Sleep is especially sensitive.”

Noise does not affect everyone equally. Housing quality, location and socioeconomic shape both exposure and people’s ability to cope with or mitigate unwanted sounds. “If you can afford better housing conditions, such as buildings with good insulation or access to a quieter side, you are often better protected. If you live close to a highway or industrial activity, your exposure is higher.”

She is particularly interested in how these patterns overlap with socio-demographic factors. Many of the health impacts of noise accumulate quietly over time, and the negative effects of noise often remain unseen and unreported. “But the absence of complaints does not mean the absence of harm.”

Expertise of Rotterdammers

Rotterdam is a particularly interesting case. As Europe’s largest port city, it produces noise day and night. Sound travels easily across water, reaching neighborhoods far beyond the port itself. Yet many regulations focus mainly on land-based sources of noise. “That creates a blind spot,” Asadollahi Asl Zarkhah says. “Port sounds do not stop at the port boundary.”

Within the NOISELAB, the residents of Rotterdam contribute unique expertise. In Katendrecht, residents pointed out sound sources that researchers would otherwise have missed, from medical helicopters to early morning industrial activity. “Community involvement and citizen science are central to the work that we do.”

“Without speaking to people and really involving them in research, you simply do not see the full picture,” Asadollahi Asl Zarkhah says. NOISELAB builds on this approach through citizen science tools that allow residents to report sound experiences directly.

For Asadollahi Asl Zarkhah, working closely with municipal partners also shortens the distance between research and action. “It’s exciting to be able to work with the municipality so closely. It makes it very likely that the knowledge we produce within the NOISELAB will actually be used,” she says.

Looking ahead

Asked what an ideal soundscape in a port city might look like, Asadollahi Asl Zarkhah is careful not to give a definitive answer. Cities like Rotterdam, she notes, will always produce sound, particularly where industry and housing exist side by side.

Rather than offering solutions upfront, she describes her work as a process of building evidence across disciplines that rarely meet. Urban designers, public health researchers, municipal officials and residents all approach sound differently. NOISELAB, she says, is an attempt to bring those perspectives together in a shared framework.

What matters most to her is that sound is taken seriously at the early stages of planning and design, not only when complaints arise. By combining long term measurements with lived experience, she hopes the research can help cities make more informed choices about where people live, how buildings are designed and which areas carry the burden of noise.

For Asadollahi Asl Zarkhah, listening is both a method and a goal. Before cities can respond to sound, she says, they first have to understand how deeply it shapes everyday life.

Want to read more?

Click here for a recent publication by Rosa de Kruif, Rodrigo Vassallo, Sahar Asadollahi Asl Zarkhah and Martijn Lugten, examining the relationship between soundscapes and the built environment in the Rotterdam port area.