A Brooklyn Building Is Screeching. We Asked an Acoustician Why.

Photo: Google Maps

On an otherwise sleepy block in Brooklyn is a brand-new 15-story building that shrieks on windy days. Residents have likened the sound to a shrill whistling, a maddening screech, and — most colorfully — a screaming dinosaur standing on top of the building. Amanda Sue Nichols, from the Cobble Hill Association, says it’s more like that “metallic screeching sound you hear on the subway.” Whatever it is, it’s nails-on-a-chalkboard annoying. And neighbors of the property at 347 Henry Street, who can hear it day and night, are at their wits’ end.

The building in question is part of the Long Island College Hospital redevelopment and is owned by Fortis Property Group. Nichols says residents first began picking up the screech in January, apparently after some scaffolding was taken down. After the Cobble Hill Association raised the issue, Fortis is consulting an acoustical engineer and believes it can remediate this bizarre problem with “an adjustment to the balcony railing.”

So what exactly is making the building sing? Alan Fierstein, an acoustic consultant who owns a 45-year-old firm called Acoustilog, says it’s likely a few factors at play. Fierstein — who took pains to say that he has not performed tests at the building and was just offering an educated guess — pointed to the building’s scale. The tower is a 15-story project mostly flanked by brownstones and low-rise brick buildings. Since it’s one of the tallest in the area, there are no other structures to disrupt the wind around it. “So above that height, a streaming wind can act like the effect you get when you blow over the top of an empty soda bottle and create a pure tone,” he said. (These tones are especially annoying because they’re not natural sounds.)

The proverbial bottle top here may be the series of balconies jutting out on the north corner of the building, which appear to have slatted rails. Since wind in New York typically flows from the southwest toward the northeast, “it would skim right past these triangular openings,” according to Fierstein. That could produce a whistle generated by each balcony, and when multiplied by several, is amplified to create a loud whistling tone.

That’s one theory, anyway. There are other possible spots where the wind could be making a piece of the building vibrate, and the sound could even be coming from somewhere else entirely, since tones tend to bounce and can be tricky to locate. They can also sometimes form what are called standing waves, which can actually generate sound that gets louder further away from the source. These sorts of unexpected sounds are a tough thing to plan for and can’t be categorized as some sort of civil-engineering error, says Fierstein.

But they can be fixed. If the balconies are the culprit — which can easily be confirmed through measurements and tests — one possible fix could be to put up a glass shield or another relatively simple structure that disrupts some of that airflow. “There’s all kinds of little tricks you can do to make things a little bit more irregular,” said Fierstein, including experiments with the placement of different structures on different balconies to see what manages to diminish the sound the most. For all the agita the sound has caused, the potential solution could be pretty basic. Fortis, for its part, says it’s moving “as expeditiously as possible to resolve it.” The neighbors, of course, just want that sound gone. “We just don’t want to be left with a screeching sound when the construction ends,” said Nichols.

A Brooklyn Tower Is Screeching. We Asked an Acoustician Why.