home

D

r. Robert Nagel, a professor of aeronautical acoustics at NCSU, came to Oriental February 6th to brief members of the Town Board on the way sound travels. He took a quick tour some of the areas of town where the noise from bands playing outdoors has disturbed residents. At Town Hall, Nagel presented a tutorial on sound dynamics to the board and an audience of about 20 members of the public.

Nagel gave a lesson in sound to the Town Board, from left, Mayor Bill Sage, Commissioners Sherrill Styron, Kathy Kellam, David Cox, Nancy Inger and Candy Bohmert.

The professor covered a range of issues, starting out with a lesson in the ways sound can bounce around and be heard farther away than you might expect.

“You would think,” he said, “that the further you go away from it, the less you would hear the noise.” But he said, sound waves can ricochet a distance away if there are certain conditions — flat surfaces and raised speakers.

Flat surfaces reflect sound, and Nagel said that he had noticed “a lot of flat surfaces like water and concrete parking lots” near the harbor. The nearby Tiki Bar is one of the venues in town whose loud outdoor music has drawn complaints from neighbors.

“The bad news is you have water and as far as sound waves are concerned, water is the same as a steel plate, pretty much. It’s just a hard surface that reflects.”

The reflection or bounce of that sound is even greater, he said, the higher the speakers are. At the Tiki Bar, the speakers are on the deck which is several feet above the ground which itself is several feet higher than the water.

“So it makes this a complicated issue,” he said, pointing to a diagram on a board, “someone says it’s not so loud here, but over here, it’s actually louder.”

The professor also noted another surface that the sound waves were reflecting off of: the three-story condos facing the Tiki Bar stage. The sound waves leave the speakers, hit the side of that building and then bounce up the Duck Pond and beyond.

The conditions he outlined confirmed the concerns that nearby residents have had since the condo complex at the Tiki Bar went to 3 stories and all the music was played outdoors.

Dr. Nagel offered several suggestions about mitigating some of those conditions, such as pointing the speakers in a different direction. But he cautioned that it might take care of only one part of the problem — the high frequency sound waves. The more difficult issue are the low frequency waves that come from the bass section of the bands.

Diagrams were necessary.

“Music these days has a lot of bass in it.” he said. The problems Oriental is facing, he said, “most likely are low frequency noises. They carry like crazy. They wrap around corners. It gets through. It goes greater distances.”

While suspending a drape or some sound-absorbing material along part of the TIki Bar stage might absorb some of the high frequency waves, he said, it wouldn’t do much to prevent the long, low frequency waves from escaping. “It’s not absorbed as easily. Any barrier you would want to put up would not have much effect unless it’s massive… hanging a blanket is not going to do.”

What might contain the bass lines, he said, was a wall. “The low frequency noise will only be stopped by mass.” Dr. Nagel defined mass as “something that will hurt your back when you pick it up. Something that’s heavy,” he said. “Solid concrete blocks would be better than the ones with holes in them.”

Those remedies might lessen the impact of the noise coming from the Tiki Bar, which had “permits” for more than 40 occasions of live music in 2008, many of them loud enough to prompt neighbors to complain to police. However, there are other venues in town where the noise disturbs nearby residents, as well. It is with all those venues in mind that Town Commissioner David Cox drafted a change to the current Noise Ordinance that would set specific noise levels.

In the proposed change to the noise ordinance, allowable levels would vary by time of day and zoning district, and would permit noise up to 75dB, measured 100 feet away from the speakers. Under Commissioner Cox’s draft, the dB level could not exceed 65 dB in the town’s residential lots.

Diagram showing the way some of the sound waves radiate from the Tiki Bar and on to the still waters of Oriental’s harbor .

Some connected with the Tiki Bar in particular, have suggested that bands couldn’t play under those criteria. Commissioner Cox’s draft includes predictions of how loud music could be played at the bar and still comply with the proposed rule. He has calculated that a band could be playing at 95 decibels (measured 10 feet from the speaker) and not exceed the 75dB level at 100 feet away.

At the meeting, county resident and sound engineer, Perry Cheatham presented some of his observations of the dynamics of not only sound, but crowds and bands. He addressed conditions he has seen at the Tiki Bar, which he frequents.

“If you’re on the Tiki Bar deck and have crowd of people and they’re talking,” Cheatham started, “and they’ve been drinking and they’re talking loud, and you have kind of a floor level that the band has to play above to be heard, right? Depending on how drunk people are, my experience is that it’s between 80 and 85 dB.”

Cheatham mentioned that the federal Occupational Safety and Health Administration, which oversees working conditions, had weighed in on the matter. “OSHA has come up with some regulations,” Cheatham said, “that set a ‘disco level’ for amplified music — generally it’s recorded music — a maximum level of 90 dB on site. The reason for that is that above that level over eight hours you start getting permanent hearing loss. OSHA regulates that because you have people that work there.”

Cheatham spoke of his experience running sound boards for performances.

“It’s a funny thing I’ve had to deal with a lot. When you have a crowd of people in a room just talking, I typically see 80-85dB. If you bring a band in there and people want to listen to the band, then the talking will stop. If you have a small bluegrass band, unamplified with a gruop of people there who want to hear the band, they’ll shut up to hear the band.” said Cheatham. “If, on the other hand, you got a band people are not interested in hearing, just there for background noise, people are more interested in talking. The louder the band plays, the louder people will talk.”

Cheatham said it was a problem he encountered in running the sound boards in clubs.

“You’re fighting a losing battle. The band is saying, ‘We’re not loud enough, we need to hear above the conversation, turn it up 5dB.’ And the crowd starts screaming at each other.” Cheatham said that he has decided on decibel levels that he won’t exceed, “so that we don’t hurt ourselves and our audience. At some point we just have to say, ‘If the crowd doesn’t want to hear you, that’s your problem as a band. It’s not my problem as a sound engineer.’ I’ve found, in my practice, that you can run a live band at 85-90 dB and generally please the band and generally please the audience.”

Cheatham also brought up the issue of the monitors, the speakers on stage facing back at the band so they can ‘monitor’ their sound. He pinpointed them as a significant part of the noise emanating from the Tiki Bar.

“The sound on the stage will usually be a lot louder than in front of the band.” Cheatham said, noting that the monitors are “a problem that shows up — especially when it’s an older band.”

“This is a problem definitely showing up at the Tiki Bar. I’ve watched this happen: People say, ‘turn it down’ and the house guy turns it down (ed:on the speakers facing the audience) but the monitors don’t go down.”

The monitors facing the band send that sound out the back of the stage and on to the harbor. As a result, Cheatham said, while the volume coming out of the speakers facing the audience may have been lowered, “the perception on the street is that the music has not been turned down. And in fact, it hasn’t.”

He suggested that one way to solve that problem is to have musicians monitor their sound thru earpieces.

Dr. Nagel takes a close look at one of the decibel meters. Comparing them to the more expensive model that he has, he said the cheaper meters were taking readings like his was.

While much of the discussion focussed on reducing the Tiki Bar’s second-hand noise with drapes, or walls or headphones, those steps would not necessarily solve the problems that residents living near other venues — the Harbor Deli, the former Scoots restaurant, the Steamer — have complained about. One member of the audience encouraged the board to set an allowable noise level with specific numbers.

Oriental resident John Griffin, husband of Commissioner Kathy Kellam, spoke from the audience and said that “hundreds of other towns have struggled with this problem and established certain levels of decibels that are accceptable.” He said that they generally settled on 65 dB being an acceptable level at the “receiving” property. He asked Professor Nagel if that were a reasonable number for Oriental.

The professor said he didn’t want to “comment on the psycho acoustics.” and said that setting the numbers was something for the Town Board to do. He did offer advice on the decibel meter the town buys, suggesting that it be calibrated before every use and that it use a weighted or averaging scale.

Posted Sunday March 1, 2009 by Melinda Penkava