An Opportunity Lost? GM’s Saturn Division – Success Squandered or Just Delayed?
Early in my career, I was a young acoustics engineer working at the General Motors “Noise and Vibration Laboratory” (NVL) where our function was to provide automotive noise and vibration control solutions to the various vehicle development teams. At one point, my job was to lead the design and development of the noise control (“Sound Package”) solutions for the original Saturn vehicle line. So when I saw the recent news about Roger Penske & Penske Automotive Group acquiring the Saturn brand from General Motors, I found myself thinking back on the glory days of Saturn: what made them so unique, and what solutions will bring them through the current economic recession? (more)
Sick of Loud and Noisy Patient Rooms? We Are Too.
You don’t have to spend a lot of time in hospitals to find out that patients are sick of the noise in their rooms. Press Ganey surveys, current literature on the subject, and the unsolicited comments we receive while measuring sound levels in hospitals all confirm that patients are most often displeased with the noise experienced in hospital patient rooms. Minimizing noise disturbance to patient rooms is an important aspect of acoustical design for healthcare facilities. But before we can reduce the noise levels, we need to know the sources of noise and understand the factors that influence its transmission. (more)
Noise Pollution from Wind Energy – Why It’s a Problem!
With today’s heightened awareness about energy and our dependence on foreign oil, we are being lured with a promise of bountiful, cheap electricity if we simply harvest the energy from the wind. As is true with everything in life, “there is no such thing as a free lunch”. Communities across the country are learning from past mistakes (the hard way) that one of the greatest struggles with wind turbine development is in community noise disturbances – or noise pollution. So, what can be done about it? (more)
The Problem with Pulpers | Noise and Vibration Control
We were recently called in to assist in addressing a noise issue that was the result of a university’s desire to be more “green”. In this case, we were asked to assess the noise produced in the dish wash room of a university student union. This blog is the second of a two-part post about student union acoustics, and you may want to read the first blog on College Campuses and Student Union Acoustics before continuing. (more)
If It Sounds Like Noise to You, It May Be “Esion”
Fundamentally, sound is “that which we hear”. What we hear at any given time can greatly influence us. We use sound to communicate, to express warning, fear, pleasure and excitement. Some sounds can relax us and help us fall asleep, while other sounds can distract us and make it more difficult to perform simple tasks. Different sounds can be soothing and pleasing or annoying and irritating. Accordingly, determining “What is sound?” and “What is noise?” can become a highly subjective task. As engineers and scientists, it’s our job to generate generalized models that have a high level of correlation to humans (or to specific populations). (more)
When One Size Does Not Fit All | Diffuser Sound Levels
On a recent trip to India, I discovered a cute clothing sizing term called “free size” which is equivalent to “one size fits all”. Free size clothing must be a manufacturer’s delight since production and distribution are greatly simplified. Adjustments to the size of the garment are typically made through waist ties of various designs and if needed, permanent alterations.
In the A/E/C industry, diffuser, grille and register (air device) manufacturers have chosen the free size philosophy when it comes to providing sound data. (more)
College Campuses and Student Union Acoustics
At Acoustics By Design, we regularly consult on the design of College and University buildings including classroom buildings, dormitories, athletic facilities, performing arts buildings, libraries, research buildings, and student centers. These numerous building types result in our needing to address a myriad of acoustic and vibration issues. Many student centers and student unions face a similar problem: loud noise from the commercial kitchens inhibit the relaxed social environment for the students. Universities want their student unions to be a center for campus life and activity, and if the student center is too loud to provide the desired environment, students will inevitably congregate elsewhere. (more)
Elbows vs. Sound Attenuators: Interchangeable?
It is common belief that a series of elbows near an air handling unit (AHU) can accomplish the same insertion loss as a manufactured duct sound attenuator. It’s true that elbows are less expensive than sound attenuators, but what acoustical performance is really achieved with this “low cost” substitution?
Let’s compare the two designs. Using the tables presented in the 2007 ASHRAE Handbook – HVAC Applications, for any type of elbow (round, rectangular, acoustically lined or not), the width of an elbow (in the plane that it turns) must equal or exceed 30 inches to get ANY insertion loss at 63 Hz. A 30 inch wide elbow provides only 1 dB of insertion loss (IL) at 125 Hz . These two frequencies are typically of concern when reducing sound from AHUs.
Why Courts Need an Expert Witness in Acoustics
Our company president, Kenric Van Wyk, was recently featured in a Wood TV 8 interview as an expert on noise levels. The local NBC affiliate was covering a story on a teenager who had been killed by a train after walking down the tracks while listing to an MP3 player through ear buds. We brought one of our noise meters down to the tracks and made measurements while a train went by, and the story made the evening news. (more)
Rooftop Roulette | Noise and Vibration Isolation for Air Handlers and Mechanical Units
Over the years as an acoustical consultant I’ve seen a lot of architectural firms locate rooftop air handling units over or near acoustically sensitive spaces; then they put up resistance to doing the necessary extensive noise controls that are needed for such a situation. The protest usually includes “but we’ve never had to do that in the past…” I call this rooftop roulette, because while not incorporating noise control design may have worked in the past, it does not guarantee future success. (more)
Perception Vs. Reality: What Our Ears Hear
It seems like everyone is talking about decibels these days: “5 dB of this” and “3 dB of that.” As acoustical consultants, we hear people using these metrics and often wonder to ourselves, “Do they really know what a decibel is?” Occasionally, someone is brave enough to ask the more important question, “Just how much is a decibel?” The answer to that question is, of course: well, it depends. Are we talking about physical sound levels or perceived sound levels? There is a big difference! (more)
Noise Isolation for Mixed-Use Developments
In the world of architecture, we frequently hear the term “mixed-use development,” and our firm is increasingly called upon to provide mixed-use development acoustical consulting. The term “mixed-use” generally refers to a development that incorporates residential and commercial space in a close-knit fashion. Mixed-use developments have been constructed for centuries, often taking the form of residential space above retail space – such as the shopkeeper living above the shop. As industrialization increased, mixed-use fell out of favor, and segregated land-use became popular. But late in the past century, mixed-use developments resurfaced, often with the intent of revitalizing urban areas and creating walk-able communities – as opposed to communities where a person must drive a car or take some form of public transportation to perform their daily routine. (more)
OSHA, The Occupational Safety and Health Administration, has long had policies regulating noise in the workplace. Their “Hearing Conservation Program” is designed to protect workers from suffering hearing loss even if they are subject to loud noise exposures over their entire working lifetimes. But navigating the waters of OSHA’s 1910.95 Noise Exposure Standards document can be a difficult (and daunting) task, and many industrial facilities are happy to outsource this task to the nearest hearing protection salesperson. Unfortunately in this case, ignorance isn’t bliss. (more)
How Weather Affects an Outdoor Noise Study
For many years, I worked as an acoustical consultant in Southern California. We had seasons in SoCal, but it took several years before I easily recognized the subtle differences between summer and fall or between winter and spring. Summer brought daytime temperatures in the 80’s while wintertime temperatures tended to range in the upper 60’s. But for the most part, the temperate climate meant that days would be warm, dry, and sunny and nights would be cooler, dry, and cloudless. My point: long term monitoring of outdoor noise levels and sound propagation was easy.
After ten years on the West Coast, I returned to the Midwest to work for Acoustics By Design, Inc., and found myself back in the midst of weather – real weather – blizzards, sticky summers, and thunderstorms. Most people know that weather can influence sound propagation, but by how much? (more)
The Wailing Industrial Demon Next Door
I am not about to compose a post vilifying the American industrial complex; I’m only expressing the attitude of many people that I come across who live near a noisy factory, processing plant, scrap yard, or other type of industrial facility. Perhaps in some cases, criticism by nearby residents is justified, but usually it is not, and often it is avoidable. Multiple times every year I am called in to assess industrial noise and vibration emissions to residential communities. Often I am hired by the company, sometimes by the local government, and occasionally by a residential group. And by the time I get involved, edgy relations have frequently devolved into contentious confrontations, accusations of purposeful illegalities, and claims of ill health due to noise. (more)
Subscribe via email
Enter your email address
Delivered
by FeedBurner