Urban Sensory Stacking: Designing for Every Brain [June 5th Episode]

David Carlisle

Welcome to the show, everybody! I'm David Carlisle, here with Eric Marquette, Harper Bennett, and Claudia Reese. And Claudia Reese, you're our resident urban infrastructure expert, so I want you to put us on a very specific street corner to start us off.

Claudia Reese

Alright, picture 34th and Broadway in Manhattan. Herald Square. It's a Tuesday at 5:15 PM. You've got an ambient noise floor of about 85 DECIBELS just from the traffic and the subway grating below you. You have 4,000-Kelvin LED billboards flickering at a rate your conscious brain doesn't process, but your optic nerve definitely does. And you've got the synthetic smell of roasted nuts mixing with diesel exhaust.

Harper Bennett

Wait, 85 decibels? That's basically having a LAWNMOWER running constantly right next to your ear while you're trying to cross the street.

Claudia Reese

Exactly. And for a lot of people, that's just a busy city. But for roughly 15 to 20 percent of the population, that combination is an absolute sensory nightmare. We call it "sensory stacking." It's not just one input; it's the sheer volume of competing stimuli hitting your nervous system ALL AT ONCE.

Eric Marquette

Okay, 15 to 20 percent. That's one in five people. That's not a tiny margin. Who exactly is in that twenty percent?

David Carlisle

Well, I can speak to part of that from my own house. I've got two kids who fall under the umbrella of... I still trip over this word after five years. NEURO-DI-VER-SITY. Neurodiversity. People with autism, ADHD, sensory processing differences. But Harper, you're the occupational therapist here, it's broader than that, isn't it?

Harper Bennett

Way broader! It includes people with PTSD, migraine sufferers, the elderly, people recovering from concussions. And to understand why a street corner like Herald Square is so overwhelming, you have to throw out the idea that we only have five senses. We actually operate through a "Sensorial Prism" of at least EIGHT senses.

Eric Marquette

Wait, eight? I get sight, smell, hearing, taste, touch. What are the other three?

Harper Bennett

Vestibular, which is your sense of balance and spatial orientation. Proprioception, which is knowing where your body parts are without looking. And interoception, which is sensing your internal organs—like knowing you're hungry, or feeling your heartbeat accelerate.

David Carlisle

Interoception. That's the one that always fascinated me. When my students get overwhelmed, it's often because that internal alarm bell—that interoceptive spike in heart rate—is being triggered by the external environment.

Claudia Reese

Which brings us right back to urban design. For decades, our baseline for "inclusive design" was strictly ADA compliance. The Americans with Disabilities Act of 1990. We focused ENTIRELY on physical mobility. Ramps, elevators, curb cuts. And as a wheelchair user, Harper, you know how vital that is. But we completely ignored the sensory and cognitive landscape.

Harper Bennett

We absolutely did. A ramp gets me into the building. But if the lobby has echoing acoustics and strobe-like fluorescent lighting, my autistic friends can't stay in the building. Designing from the margins means realizing that a neuro-inclusive environment—one that manages that sensory stacking—actually creates a calmer, better space for everyone.

Eric Marquette

You know, it's interesting you mention lighting and acoustics, because we're actually seeing this play out in the commercial sector right now in a massive way. In the summer of 2023, Walmart announced they were bringing back "sensory-friendly hours" from 8 AM to 10 AM, every single day, across the US and Puerto Rico.

David Carlisle

Every day? I knew they did it for back-to-school, but I didn't realize they made it a permanent daily fixture.

Eric Marquette

Every single day. They change the TV walls to a static image, turn off the store radio, and dim the overhead lights. And Tesco in the UK has been doing a similar thing with their "Quiet Hour." But here's the kicker: Walmart rolled this out to over 4,700 stores.

Claudia Reese

4,700 STORES. That's not a cute little pilot program. That is a national infrastructure shift. When the largest retailer in the world standardizes something, it changes the baseline expectation for commercial space.

Eric Marquette

Exactly. And there's a hard business case for it. If 20 percent of the population finds your store physically painful to navigate, you are losing their money. Plus, the families of those individuals. When they instituted these quiet hours, they found that neurotypical shoppers actually preferred it too. People stayed longer and bought more when they weren't being bombarded by top-40 pop hits and blinding fluorescents.

Harper Bennett

I mean, who actively enjoys grocery store lighting? Nobody. But the real evolution here is moving beyond just "hours" on a clock, and baking it into the permanent architecture. We're seeing this in transit hubs now. The Pittsburgh International Airport opened a multi-sensory room—they actually call it a "Presley's Place"—which has soundproof spaces, adjustable lighting, and even an airplane cabin mock-up.

Claudia Reese

Yes! And from a structural design perspective, we're starting to use something called "Prospect-Refuge" theory. It's an evolutionary concept.

David Carlisle

Prospect-Refuge? Like, surveying the land and hiding?

Claudia Reese

Exactly that, David. It was coined in 1975 by a geographer named Jay Appleton. The idea is that humans feel most comfortable when they have an unimpeded view of their surroundings—the prospect—while their back is protected from hazards—the refuge. Think of sitting in a cozy booth at a restaurant looking out the window, versus sitting at a table right in the middle of the floor where waiters are rushing behind you.

Harper Bennett

Oh, I absolutely refuse to sit at the middle table. Give me a wall or give me death!

Claudia Reese

Right? And now, urban planners are actively building Prospect-Refuge into public parks and plazas. Creating these alcoves and recessed seating areas where a neurodivergent person can retreat, decompress from the sensory load, but still see the environment so they don't feel trapped. It's brilliant.

Claudia Reese

And that brings us to the actual blueprints of how we scale this up. In urban planning, there's a rising model called the Sensory Responsive Environments Framework—SREF. One of its core pillars is using nature as an acoustic and visual buffer against urban chaos.

Harper Bennett

So wait, SREF... is that just planting more trees? Because I feel like "plant trees" is the urban planner's answer to everything.

Claudia Reese

Fair pushback, Harper! No, it's much more specific than just "trees." It's about breaking up repetitive visual patterns. If you have a massive brick wall or a perfectly geometric glass facade stretching for 200 feet, that extreme, unnatural repetition can actually trigger visually induced dizziness in some people.

David Carlisle

Oh, wow. I've seen students get overwhelmed by the checkerboard tiles in our school hallways. It's the same principle!

Claudia Reese

Exactly the same principle. SREF mandates integrating organic, non-repetitive shapes—like specific types of native landscaping, or asymmetric architecture—to break up those harsh, triggering lines. It also emphasizes clear landmarks over generic signage.

Harper Bennett

Which is a massive deal for cognitive predictability. If you have extreme anxiety or cognitive processing differences, a city that looks the same on every block is terrifying. You need a giant, weirdly shaped fountain, or a bright mural, to anchor your sense of place. Predictability lowers the interoceptive stress response we talked about earlier.

Eric Marquette

You know, listening to all this—from the Walmart quiet hours to the non-repetitive architecture—it feels like we're finally moving past viewing accommodations as a favor we do for a small group. It's actually just... better design.

David Carlisle

It is better design. But it leaves me with a lingering question. For so long, people with disabilities have just been the passive recipients of whatever accommodations able-bodied designers decided to give them.

Harper Bennett

Yup. "Here's your ramp, be GRATEFUL."

David Carlisle

Exactly. So, as we rebuild our cities for this new neuro-inclusive standard... how do we ensure the neurodivergent community is actually in the drafting room? Not just as focus groups, but as the lead architects and planners of the future?

Claudia Reese

That is the exact right question to end on, David. If we want cities that work for all eight of our senses, we need the people who feel those senses most acutely to draw the blueprints.