During the regular City Council meeting on Feb. 28, the city heard from Joe Lema, a local sound engineer, about his special event sound monitoring efforts.
“Joe came to us several months ago and offered to conduct unofficial sound monitoring of some of our louder events, and put together some statistics for you guys to look at,” said Mayor Joette Langianese.
Lema did sound readings on several events: all the Moab Free Concert Series events held over the summer, the Moab Folk Festival, and the Scots on the Rocks Celtic Festival.
In April of last year, the city council, in a 3-2 vote, denied the Scots on the Rocks festival a permit to hold the festival at the Center St. Ballparks, saying some residents thought it was too loud (councilmembers Jason Taylor and Tawny Knuteson-Boyd dissented). At the time, Taylor pointed out that other loud events, such as the Moab Folk Festival, are held at the ballparks. The Scots on the Rocks festival organizers resubmitted their permit application with plans to mitigate noise, and in June, the council voted to allow the festival at the ballparks in another 3-2 vote (councilmembers Rani Derasary and Kalen Jones dissented).
The summer concert series and Folk Festival both clocked lower average decibel readings than the Scots on the Rocks festival, though all three events had high peaks. Scots on the Rocks had a higher average noise level because the noise produced at that event remained largely the same, but its peak volume was lower than that of the other events.
“Bagpipes are not a dynamic instrument—they’re one volume all the time,” Lema said.
Every increase of 10 decibels on the decibel scale is equal to a 10-fold increase in sound pressure level: according to Yale University’s decibel level comparison chart, a normal conversation usually clocks in at 60-70 decibels, a vacuum cleaner around 75 dB, a power mower at 107 dB.
According to Lema, the opening ceremony of Scots on the Rocks had a peak reading of 76 dB within the ballpark (the peak reading isn’t a constant, Lema said, it’s like a burst of sound), and when 20 bagpipe players warmed up by playing “Amazing Grace,” their noise reached 82 dB. During the festival’s bagpipe playing competitions, noise levels hit 68 dB. Lema also took readings from nearby residents’ yards, which ranged from 43 to 48 dB.
Lema said he combined the data for all the summer concert series events at Swanny City Park, since the noise was well-regulated at each. Decibel readings were taken 10 and 75 feet back from the center stage: at 10 feet, the noise had an average reading of 87 dB with a 92 dB peak. At 75 feet, the average was 67 dB with a peak of 79 dB.
The Folk Festival, also held at the Center Street Ballparks, reached higher decibel readings, Lema said. A few times during the festival, noise levels hit a peak of 97 dB, which is over the legal limit of the city’s noise ordinance (92 dB). Lema measured the sound at the same residential yards, finding that it ranged from 48 to 57 dB.
So, according to Lema, the Scots on the Rocks event was a bit quieter overall than both the summer concert series events and the Folk Festival, but it did have more sustained noise.
“I think there are definitely some things that can be addressed, as far as how to keep control of volume,” Lema said. “I think everybody doing festivals needs to have that reminder of what the restrictions are and that there will be people watching.”
The council said they aren’t sure yet if noise monitoring to this level will be done at every event, but for now, they at least have a few numbers they can point to when noise issues come up.