Tom McCall Waterfront Park sits right next to I-5. If you’ve ever been there, you know: the freeway is loud. Constant white noise baseline. It doesn’t stop. It doesn’t pause. It just is.

Here’s the weird thing.

When I took practitioners on soundwalks through the park, do you know what sound they noticed most? Not the freeway. The freeway barely got mentioned.

They noticed:

• Bikes bells
• Fountain splashing
• MAX train rumbling across the Steel Bridge
• Helicopter landing on the nearby parking garage
• Saturday Market crowd murmur

One person even commented on the sound of joggers’ feet on the pavement.

The freeway—the single loudest element of the park’s soundscape—was functionally invisible to their ears. Not because it wasn’t there. Because it was always there.

This is the freeway paradox: the most pervasive sounds become the hardest to consciously perceive.

Your brain is lazy (in a good way). It’s constantly filtering input to focus on what’s novel, threatening, or useful. Constant sounds that don’t signal danger get pushed into background processing. You’re still hearing them—neurologically, your auditory system is still registering those frequencies. But consciously? They disappear.

Until you close your eyes and actually listen.

That’s what happened on the soundwalks. I didn’t tell people what to notice. I just asked them to listen. And suddenly that freeway roar came crashing into their awareness like it had just been turned on.

Several people literally said some version of: “Whoa. I didn’t realize how loud that was.”

One urban planner told me: “I’ve been to this park dozens of times. How did I never hear that before?”

Because you weren’t listening. You were looking.

This is the fundamental problem with how we design cities. Vision dominates. We train architects and planners to think visually. We evaluate public spaces through photographs. We talk about “sight lines” and “visual interest” and “aesthetics” but rarely mention sonic character.

The result? Spaces that look beautiful in renderings but sound terrible in reality.

And because the worst sounds are constant—traffic, HVAC, ambient urban hum—we don’t even register them as problems until something breaks. Until a specific noise complaint forces us to pay attention.

This is why traditional noise control fails. It only responds to acute sounds: the leaf blower at 7am, the concert that goes too late, the neighbor’s dog. Chronic sounds—the ones actually shaping your daily experience—never trigger the complaint system because you’ve already adapted to them.

You’ve had to adapt to them. If your conscious mind focused on every constant sound in your environment, you’d go insane. So your brain filters. It prioritizes. It decides what’s foreground and what’s background.

This is physiologically necessary but planning-wise catastrophic.

Because it means the foundational soundscape of a place—the acoustic baseline that determines whether that space feels calm or chaotic, safe or stressful—is invisible to the people designing it.

Let me give you another example. There’s a “quiet plaza” in downtown Portland. Beautiful space. Trees, benches, small fountain. Designed explicitly as a respite from urban noise.

I measured the sound levels. 75 decibels average. That’s equivalent to standing next to a busy road. Or a loud restaurant. Or a vacuum cleaner.

The plaza isn’t quiet. It just feels quieter than the street because the building ventilation systems create consistent white noise that masks more variable sounds. Your brain interprets consistent sound as “quiet” even when it’s objectively loud.

This is what drives me up the wall about purely measurement-based noise regulation. Decibel levels tell you almost nothing about perception. Two spaces can measure identical sound levels and feel completely different based on sound character, variability, and context.

A park that measures 70 dB from bird song and rustling leaves feels worlds apart from a park that measures 70 dB from traffic rumble. But if your only tool is a sound meter, they’re the same.

This is why soundwalks matter. Why I drag practitioners into parks and make them close their eyes and actually listen. Because you cannot design soundscapes from data alone. You have to experience them.

You have to retrain your awareness to perceive what your brain has learned to ignore.

The freeway paradox shows up everywhere once you’re looking for it:

• Office HVAC that workers don’t consciously hear but that increases stress levels and reduces productivity
• Apartment buildings where residents complain about neighbors’ footsteps but not about the major street outside (because footsteps are variable; traffic is constant)
• Parks where visitors say they came for “peace and quiet” despite measurably loud ambient conditions

We’re remarkably good at adapting to terrible soundscapes. Which means we’re remarkably bad at demanding better ones.

And this is ultimately why soundscape approaches matter more than noise control. Noise control asks: “What’s loud enough to complain about?” Soundscape design asks: “What does this space sound like, and is that supporting or undermining its intended purpose?”

That second question catches the freeway. The first one doesn’t.

I’ll leave you with this: Next time you’re in a public space, close your eyes for 60 seconds. Just listen. Don’t judge, don’t analyze. Just notice what’s actually there.

I guarantee you’ll hear things you’d completely tuned out. And some of them will be loud. Persistent. Foundational to the character of that place.

Those are the sounds shaping your experience whether you realize it or not.

Those are the sounds we need to start designing for.

#SoundscapeAwareness #UrbanPlanning #FreewayParadox #AcousticEcology #DeepListening #CityDesign #SoundPerception #UrbanSound #ListeningFirst #SonicEnvironment