Hello-o-o from Pioneer Courthouse Square’s echo chamber

The miniature amphitheater uses physics and design to create interesting sound effects.

The little amphitheater at Pioneer Courthouse Square in Portland, Oregon.

Bronze relief plaques set in the bricks tell the story of Portland.

Photo via Pioneer Courthouse Square

Taking a look under the couch cushion, so to speak, at Portland’s Living Room will reveal several secrets waiting to be discovered. There’s the Weather Machine and its musical forecasts, the Milepost Sign that points you toward our sister cities, and of course the 72,000+ bricks etched with personal messages.

But did you know about the echo chamber in Pioneer Courthouse Square? To test it out, head to the little amphitheater just behind Starbucks (on the Southwest Morrison Street side). When you stand on the granite disk and speak toward the steps, your voice bounces off the hard, curved walls, and back to you at a barely diminished volume. Thanks to the design, you can also whisper from one side of the circular space, and your friend on the other side can hear it.

It’s a fascinating modern example of acoustic design that has been used since ancient times.