Here are a couple of noise articles Bernie.
An excerpt from this
A social stigma often associated with public skateparks is that they are a wild and noisy place that not only can become an eyesore but can also contribute to neighborhood noise pollution. According to the official Web site of the Skatepark Association of the United States (SPAUSA), “a skatepark has no more noise than the ambient surrounding noise that exists in other parks, and is not nearly as noisy as a baseball park” (Skatepark Association of the United States, n.d.). The reality is that the majority of noise attributed to skateboards does not come from the act of riding the skateboard.
Most people’s experience with skateboarding noise is associated with the act of skateboarding across city sidewalks. The majority of this noise does not actually come from the wheels rolling across the surface of the concrete, but rather from the cracks in sidewalks and other rough surfaces and inconsistencies. In a 2001 study conducted by the Portland, Oregon, Office of Planning and Development Review, city noise control officer Paul Van Orden found that the impact of noise on skatepark neighbors could be minimized through adequate planning and design. Van Orden found that the sound of urethane wheels rolling across a smooth surface is not inherently noisy (Van Orden 2001). The loudest noises produced by skateboards typically come from hitting the nose and tail of the skateboard on the ground or from sliding and grinding the skateboard trucks across skatepark coping and ledges.
Skateboarders will ollie or pop their skateboards into the air by hitting the nose or tail on the ground in an effort to execute a variety of maneuvers. The instantaneous noise that is created from these pops can be compared with the sound of a baseball bat hitting a ball. The noise study conducted by the City of Portland found the noise levels for popping and ollieing to be at 65 to 71 decibels (at a distance of 50 feet [15.2 m]) and found the levels for grinds or slides to be at 54 to 63 decibels. According to Van Orden, a typical conversation occurs at 59 to 63 decibels, and background noise can usually mask the majority of the sound produced by skateparks. Interestingly, a similar study from an October 20, 2006 newsletter of the LifeTips Web site found the following: “One of the most common misperceptions about skate parks is that the noise created by their users will surpass code limits and upset the community. But the reality is quite different. In a recent study, it was found that peak skate park noise levels averaged 70 decibels from 50 feet away. In comparison, from the same 50 feet away a dishwasher and toilet produce comparable decibel levels. A football game produces 117 decibels, heavy traffic 85 decibels and a home refrigerator 50 decibels. All in all, a skatepark is no more noisy than similar recreation areas like a basketball court or children’s playground” (LifeTips 2006)."
And heres one form the hippies
Actually its a full blown assessment of the park which tends to support the study above. Although it does suggest mitigation strategies.
I tried but can’t find the LifeTip newsletter mentioned, it comes up a lot when looking at noise. But I would suggest that the noise argument may not be useful with respect to a bowl. The street section will be there anyway so the addition or not of a bowl would be audio neutral.