19 November 2009

Where are the Noise Police?

This from Tucson, AZ, about "hump honkers." You have got to be kidding me. Well, Tucson residents (and police) might need to review their noise ordinance; Section 16.31(f) states: "No person may use any automobile, motorcycle or other vehicle, engine or motor of whatever size, stationary or moving, instrument, device or thing, in such a manner as to create loud and unnecessary grating, grinding, rattling or other noise." Surely this nonsense qualifies as "unnecessary...noise." If so, the risk of a $100 to $2,500 fine should be deterrant enough for these "hump honkers." <<>>
Back east in Baltimore... Um, the Baltimore Health Code (PDF) covers this (see Section 9-206), folks. It's probably not unreasonable to speculate that the sound level from the generator is over the 50 dBA nighttime limit at the property boundary, i.e., at the edge of the right-of-way. Of course, since the noise is arguably within the public interest (maintaining cell phone coverage), it's probably exempt...but the exemption must be granted by the Commissioner of Health. (Which, giving the benefit of the doubt, Sprint may have done...) Regardless, the proposal to use "bales of hay" as noise mitigation is another matter entirely!!! <<>>

31 August 2009

When More Noise is Better

Came across this little piece at the Scientific American blog site (via LinkedIn).
Go BOILERS!!!

06 August 2009

ProAV Jul/Aug 2009

In case you haven't gotten your copy yet, ProAV Magazine has a good, short piece on acoustics entitled "Collective Wisdom," which provides acoustical perspectives on four types of commercial venues from four industry experts. For the online version, it seems you'll have to tolerate some annoying Sony pop-ups. Worth it, tho'. :)

10 June 2009

Careful Where You Put That Probe, Officer...

"(Sgt. Todd) Newberry probed 20 inches into the idling Ford's tailpipe, and took a reading of 103 decibels -- 13 past the legal limit of 90."
With my curiosity sufficiently piqued by this measurement procedure, I looked up the Mansfield (OH) city code, which states the following regarding vehicular noise emissions:
"Ninety db(A) when measured twenty inches from the rear of the exhaust pipe at a forty-five degree angle to the center of the pipe at a minimum height of eight inches from a hard surface."
Hmmm... Assuming this was reported accurately, it would seem that Sgt. Newberry went 40 inches the wrong way with his, er, probe. Advice: Avoid body cavity searches in Mansfield, OH!

24 April 2009

Acoustical Miscellany

Some bits and bobs for this week / month:
Those amongst you with a penchant for sci-fi may be familiar with the steampunk subgenre. I'm not a huge fan of steampunk, but I have to admit that I hold a special place in my heart for The Wild Wild West TV show from the '60s. How does this relate to acoustics? Well, a new online steampunk publication, Steampunk Magazine, provides issues for free download. The first issue (PDF) had a couple of articles that will be interesting to the musical acoustics enthusiasts among you; check out "The Pyrophone" on page 9 and "Glass Armonica" on page 10.
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Colleague Jeffrey Fullerton, of Acentech, writes for The Journal of New England Technology about considering acoustics during the meeting planning process. Excellent advice.
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This is an interesting article on some work being undertaken at Youngstown State University on using laser scanning of large performance venues to help analyze acoustics. The article doesn't go into much detail on the how, but I think it shows promise: I can envision a future where a consultant can perform a few scans if an existing space that import the results directly into a acoustical modeling program (such as one of these). This would save considerable time poring over drawings and inputting data points by hand.
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Finally, don't forget next Wednesday (29 April 2009) is International Noise Awareness Day. Do your part to help spread the quiet! 8^)

13 April 2009

Best Public Service Announcements...Ever.

HIL.AR.I.OUS.
Today, I love the Canadians. :)

23 February 2009

Today's Forecast: Partly Sunny, Calm, 48°F...and 53 dBA???

I couldn't help but moan when I came across this column in the (Chicago) Daily Herald. All in all, pretty decent advice. But what is particularly irksome is this statement:

Acoustics certainly qualifies as a science, as does meteorology. Both are often accurate in their projected outcomes - but not always. Some concert halls, for example, have spent millions of dollars to enhance sound quality a few years after the buildings opened with supposedly superb acoustics.

So, acoustic physics "qualifies" as a science??? I don't think I'd be off-base by observing that Ms. St. Clair's comparison of acoustics to meteorology gives readers exactly the wrong image that we acoustics professionals wish to convey. Like many other scientists, acousticians can predict outcomes quite accurately. Certainly more accurately than meteorologists. Put simply, the more information an acoustician has about a situation, the more accurate the prediction. Contrast that with meteorology where, despite the accuracy and thoroughness of the input data, the slightest change in one of many, many variables can mean the difference between a beautiful day at the beach and blowing gales with driving rains.
Of course, when a concert hall is designed, there are many variables at play that can have an effect on the acoustics. However, they are all controllable variables; budget, mechanical design, interior finish details, seating design, stage design, et al. The predictive tools we use have been proven to be provide accurate results and desirable outcomes. A meteorologist with millions of dollar's worth of state-of-the-art prediction tools, reams of good input data, and decades of experience can go over a forecast dozens of times and still get it "wrong"; it's just the nature of that particular science. The slightest shift in wind direction can mean the predicted 4-8 inches of snow is actually only a light rain. A calm forecast with a high of 80°F can be replaced with the reality of gusty winds and 57°F. Missing the mark by such orders of magnitude is simply not something that happens in acoustics, unless there are extenuating circumstances beyond the acoustician's control or, indeed, completely beyond their awareness. If we're given all the information about a noise source, its path, and the receiver, we can typically predict the outcome with a high degree of accuracy. Certainly within industry-accepted tolerances. If we were subjected to the chaotic situations meteorologists face on a daily basis, we could hardly (for example) convince government agencies to spend millions of dollars on highway noise barriers.
As usual, I'm probably overreacting. But I find that these kinds of statements keep our science entrenched in the "voodoo" category, which is both unfortunate and unnecessary. IMHO. :)