Tag Archives: Vibration and Noise Control Class

More Information On Reducing Low-Frequency Home Noise and Vibration –

We received a question from a consumer regarding low-frequency home and vibration. After a response from expert staff of Acoustics and Noise instructors and a few additional posts on this general topic of interest, the response below came from the original consumer.

Dear Sir,

Here is my reply. You asked for it, and it is lengthy. I am so grateful that you all are taking your time to give me your suggestions. I think a probable low frequency noise source, in addition to the trains, and obvious manufacturers’ noises, could be an asphalt batch plant that is located just behind our neighborhood. I drove by and listened and it is quite noisy with its clattering conveyer belts, giant blower, and the huge rotating mixing bin. I doubt we could have any influence on quieting such an operation. When we moved into our present house this plant was hidden by trees. Now that the leaves are gone, it is easily seen. Let the renter beware!

We have tried all the things that were suggested in your e-mail. White noise machines and fans just added noise to the home and was not the solution I needed. The best brand of ear plugs worked well, but are kind of dangerous when you need to listen to what is going on in the house at night….like when someone might be sick and need help. ( mothers can appreciate this reason), or a tornado siren, etc. My husband must sleep and so I have the “night watch”. .The Bose headphones (thanks Grandma) did not do a thing for the low frequency, but one of my sons is enjoying them tremendously now for listening to music. I hate that she wasted so much money on something that didn’t work. I, too, have wasted lots of money buying several bundles of Fibrex to use as “bass traps” of sorts thinking that it might help. It did not.

We did the realtor thing also. We moved from our first house recently. That house has its own story. We had moved to this town from out of state and did not know much about the area. Well, the house we bought was down the street from a gas well compressor. It was hidden in a wooded area and we did not know about it. Who would ever think that such a thing as a gas well compressor would be in a neighborhood…..only in Texas. The days we viewed the house happened to be some of the few days a year that the compressor was down for repairs or maintenance. On closing day when I walked up the stairs to turn the key in the door, I said to my self, “What is that noise.” After searching the neighborhood, we discovered the culprit to be a very old noisy natural gas driven compressor on a gas well. I fought that oil company for a long time and only was successful getting them to put up a wooden fence that did absolutely no good. Oil companies are King around here. They always expressed to me that they were compliant. They were, but this city has wimpy standards and codes that do not measure low frequency. We had spent lots of time, sweat, tears and money fixing up “this old house” and we did not want to move. We had redone the wooden floors ourselves, and I did not want to cover them up with carpet, even though that might have helped with the sound. We couldn’t afford to change out the old windows that were huge and had just been refurbished by me. Our home was built in an L shape facing the compressor. This was perfect for capturing the “waves”. They came right in through our large glass windows. In addition to that, there were metal awnings over each window acting like ears to reflect the sound in through the single pane windows. (I had refurbished those as well) The neighborhood was refreshingly quiet on the few days that “The Beast” was off for one reason or another.

After three years of torment, the for sale sign went up. We disclosed the noise ( which probably brought our home value down) to the new buyer. She was not home much of the time anyway so she was not as bothered by it. The search for a quieter place was on. We were scared to think of buying again without knowing if “the sound” would be in that area too. , “ I had gone to look at houses for sale, just to see if I could hear how the house “sounded” and just to “test” a neighborhood. We decided just to rent. Little did we know that rental homes that are large enough for our family of six and that are in our price range are extremely hard to find in our town. We ended up having to grab a house when it became available just to get a decent place to live. As it turns out, we ended up moving from one frying pan to another frying pan so to speak. We have now been living in this rental for ten months and we are still plagued with noise problems. I say we because even though the others of our household are not as sensitive to LFN as I am, they still have to live with someone (the mom) who is and whose daily life is not as efficient as it could be were I able to sufficiently rest and relax. I went with our church on a mission trip to Mexico a couple of years ago. While up in a quiet mountain village, I discovered how wonderful peace and quiet were, and I realized just how much that LFN affected me while living in our bombarded home.

Since we now rent, I can’t beef up the windows, but I have heard that double panes do not help with low frequency anyway. I’ll try to make a window plug to see if that helps. I can’t run the TV “off channel” because we need to concentrate and study at home. We are one of those homeschooling families. Also, that noise is annoying to my teenage daughter and me.

You asked about whether or not other neighbors have had the same problems as I. I can’t tell you that. We haven’t gotten to know our neighbors very well yet. There are some factors to remember when questioning the neighbors about noise problems. Many in our neighborhood are retired and wearing hearing aids. They, of course, do not have problems with the noise. Second, if they did hear the offending frequency, they would be hesitant to say so in fear that this information might be something that could “go public” and cause their home values to go down. Third, low frequency noise is most often a source of annoyance to those fifty and older (I give away my age). The younger ones in the neighborhood have not yet reached that point. On a side note, there is an old man in the neighborhood who sits out in his attached garage with the garage door up for many hours a day. He will even sit out there when it is 100 degrees outside. I am just curious if he has a problem with LFN and is trying to escape it as I am. By the way, when I am out working in my ten by twelve foot shed (made of that composite siding stuff and sitting on wooden skids) I can’t hear or feel the vibration. This makes me wonder if the noise could be possibly ground borne. The LFN does seem to be worse when it is raining…..hum….saturated soil conducts noise very well doesn’t it. If the LFN was ground borne, would ….putting down a wood or laminate flooring that had a good coating of Green Glue behind it help. Is there any conclusive way to determine if LFN is indeed coming through a concrete slab? (I know this is some of that thousands of dollars of advice coming my way.) As was suggested, I am going to try to decouple the bed from the floor. I’ll order some sheets of sorbothane for that purpose. They are supposed to work better than rubber. What kind of instrument would measure the wall or slab vibrations?

My son, who is now an engineering major (ME), once measured the sound with a microphone on his computer. Using music recording software, he measured the frequencies from 30 to 60htz or so. He had fun isolating the sound and turning it way up for all to hear and feel till we yelled at him to shut it off….ah teens. He captured it in the tile shower. So I know it is “out there” and not just “in my head”. It could be that I am one of those “hummers”. Read about them online. They can hear the Kokomo Hum, the Taos Hum, the London Hum, etc. There is even a low frequency sufferer’s society. This is your market for whoever invents a comfortable low frequency blocking head gear that can be worn at night. This wouldn’t block (as ear plugs do) the types of noise that parent’s need to hear at night.

I would be interested in any tests like the one that one of the teacher’s mentioned ….measuring the frequency outdoors and comparing it to the indoor reading. I guess I just have to rent a device that measures what I need to measure. We would like to move, but as I said previously, I would not like to buy a home without knowing that I can block the offending noise that this town seems to produce whether from trains, underground gas pipes, well drilling, or chemical and manufacturing industries, etc. If we were to rent, we could not spend lots of money to “treat” the house for LFN. My husband likes his job and would like to stay in the area if possible. Me, I’d rather move to a small mountain village in Mexico. Or until then, I’ll just sleep with a pair of sorbothane shoe insoles smashed over my ears.

I am glad you are teaching classes to train engineers in ways of mitigating noise and vibration, because ultimately these problems have a personal side and a personal face. If I have been a “textbook” case for you then so be it, and may you all become the best problem solvers in this area. If any of you have any other suggestions for me, send them my way. If you solve my problem, then my hat is (or should I say ear plugs are) off to you. Please do not share my e-mail address with the masses.

My humble thanks,

C

Home Low-Frequency Hum – House Is Literally Humming

The issue of home low frequency hum is discussed on several blogs. I did some searches om Home Hum Noise

RE: House is humming, literally

* Posted by kevin2009 (My Page) on
Fri, May 1, 09 at 18:22

Have had exactly the same problem.
Problem so bad its been giving neighbours headaches-sleep pattern deprivation etc etc.
A low resonant humming getting stronger at night etc etc.
Not caused by traffic,electricity etc.
Humming caused by water pipe vibrations causing all sorts of low frequency bass like wooing noises.
Have found the problem tonight – pressure variance in water mains pressures.Too much pressure causes pipes to hum.
Possible causes – pumping station pressures too high – pressure reducing valves malfunctioning – mains pipes causing transient noise due to a “Dead end” section of the mains pipe.

Symptoms that can be checked – when the hum is at its loudest turn one of your taps on – the hum may reduce if the pressure lessens in the mains supplying the house – have you noticed any high flow/pressure rates from your taps?
Not certain but a loss of water pressure may have similar properties also.

If in doubt get your water utility company to do a flow/pressure check on the mains /in your house etc.

The turning tap on trick will only work if its sufficient to
reduce the mains pressure – if not try to get neighbours etc to turn theirs on at the same time etc.

I live in england in wales in Newport.
I will now update my posts when the utility company is made aware of the cause of my problem and tells me how they are going to fix it.

This is a problem with humming that for me has been caused by mains water supply pressure problem – not necessarily your problem.Simply turning the stop cock to your house off is not enough – the problems still there because the pipes are still singing to the pressure problem.

Hope this helps somebody.

RE: House is humming, literally

* Posted by peachiepie (My Page) on
Tue, Jun 23, 09 at 17:31

Wow, I do not believe that so many people has the problem I have been having for three years. I am amazed when someone suggests tinnitus. I have explained I hear humming, not ringing. It is a sound and not a noise. Mine sounds like a low hum of a refrigerator or a motor lowly idling.

I have had plumber, water, gas, power, and anybody else you can imagine here in my house in Georgia. This is a 1970s house and the hum began about two weeks after having a new water heater installed. The pressure was too high and the plumber came in and corrected it. Two weeks later, the hum began.

I don’t get a complete night’s sleep at all. What little sleep I get comes from le4aving the tv on late and then turning the radio on. Now, I can run the attic fan all night so I don’t have to hear it.

Some people have heard it and others haven’t. I stopped mentioning it for fear people thought I was losing my great mind-lol. People still ask me time to time if I still hear it. I tell them yes. When the power is out, it’s just me and the hum. Drives me nuts. It is 24/7, never stops and in every room of my house. You can’t escape it.

I had a client in my office and he asked, “what is that”. I said, oh you hear that. He said yes, what is it. I said, I wish I knew.

There are a couple of things here that’s given me some hope. I will try the water trick, though I believe my plumber did all of thesse things. I will have the telephone company come out to check the lines. Everything else, I believe I have done.

Good luck to all of us living with this in all areas of the country.

Peachie

Low Frequency Home Noise Continued – Another Expert Opinion – Understand How The Noise Is Getting Into The House

See the previous post from Carolyn about low frequency noise in her home that bothers her sleep and living.

Jim,

There may be a question about how the noise is getting into the house, whether by airborne transmission of noise outside or ground borne vibration into the structure of the house with noise radiation due to floor/wall vibration. Carolyn said they hear the noise inside but not outside which would suggest that it is ground borne. Also, there are train tracks in the area that where the locomotives sit idling all night. These could be a source of both airborne noise and ground borne vibration at low frequencies. If the problem involves ground borne transmission then modifying the windows will not do much as the path does not involve transmission through the windows. Also, are the vibration at levels sufficient to be feelable by the inhabitants?

It would be good if measurements could be carried out to reliably determine whether the transmission is airborne or ground borne. At a minimum, measurements are needed to monitor actual levels of noise inside and outside the house to determine a frequency spectrum of the noise and to establish a correlation between outside and inside levels when the noise occurs. It would be good also to monitor floor or wall vibration levels along with ground vibration levels outside around the house. These measurements would quantify how the noise is getting into the house as a basis for deciding how best to approach reducing it.

The suggestion about adding a second pane to the windows should help if the transmission is airborne and the windows are the weak link in blocking transmission through the outer walls of the house – brick should be heavy enough for the solid walls, leaving the windows and possibly the doors. Dealing with ground borne transmission would be more complicated as decoupling the foundation and structure of the house from ground borne vibration transmission is not easy.

In non-engineering terms, have the people been in the house for a while?, is this a new problem that developed recently?? Your wondering about contacting someone in public administration about local noise standards is good. Also, are there neighbors with the same issues that could be brought into the pursuit of a solution? We often have community noise problems where a group of neighbors are involved in seeking solutions with the offending company, who is often willing to pursue a solution to maintain good community relations and may be willing to pay to develop a solution.

I would be willing to communicate or talk with Carolyn directly about the problem. We are consultants but would be willing to discuss things in a preliminary fashion.

Jim Moore

Reducing Low-Frequency Home Noise and Vibration – “You don’t need a noise control engineer, you need a real estate agent.”

ATI maintains an “email this instructor” page. Normally we expect questions about the course content or follow-up questions after the course. However we received this question from a consumer and responded to her Home Noise question. We do have an expert staff of Acoustics and Noise instructors, and this appears to be a general topic of interest.

We solicit and will post other successful approaches to reducing home noise and vibration.

Date: Fri, Mar 5, 2010 at 9:26 AM
Subject: vibration and noise control course teachers
To: aticourses2@gmail.com

Dear Sir,

After reading about this course I thought I might ask the teachers if they might be able to help me to determine how to stop the rooms inside my house from vibrating with low frequency noise? The smaller the room (like a bathroom, tile shower, or closet) the worse the noise. We live in an industrial area and also an area with lots of trains that sit on tracks in a train switching area and just rumble (and consequently vibrate) all night. Also there is lots of oil and gas well drilling and compressor activity in the area. It seems that there should be a solution to stop the vibration reverberating within the house! At times the noise is only detectable inside the house and not outside. This is a brick house with single pane windows. During a several hour power outage a couple of weeks ago I could still hear the rumble, so I know it is not some electrical apparatus inside our home. I am positive we are dealing with an outside source. Would painting the wall with one of those visco elastic polymers meant to damp vibration help? I have seen Quiet Car and Silent Running as examples of these for sale. I have also read that Green Glue and another layer of sheet rock might keep out low frequency noise. Would putting bass traps in the corners of the rooms help? Would a sheet of say low durometer Sorbothane covering the window solve the problem? It is very much a problem by ruining concentration and causing lack of sleep and a high level of stress. Any help would be appreciated. All these materials are very expensive, so I would like an expert’s advice before I spend the money on them. If these products would work to solve the problem, they would be well worth it, though. At night, I have even resorted to trying to fall asleep with a shoe insert (meant for absorbing the shock of walking) covering each ear (these were made with a layer of Sorbothane). It blocked the low frequency better than anything else I had tried, and they were soft. Desperate people resort to desperate measures. I even thought about buying a wrestling head gear (low profile) and lining the ear part with a sorbothane sheet. At least I could sleep in peace, free from low frequency torment. All you inventers out there take note. According to what I read on the internet, there are many people like me that are needing relief. Any recommendations?

Sincerely,

Carolyn

1. – Jim Jenkins responded

I would say adding storm windows would attenuate the mid-frequency noise through the window.

Alternatively a white noise or background music or nature sounds box would help mask the noise. There are several commercial boxes sold to help sleep. You can test this with a small fan before buying a commercial product.

2. – Eric Ungar responded

Ear plugs might also be a good idea.

I doubt that a white noise box would help, but she might try out the concept by using his radio or TV, tuned between stations.

As one of my colleagues likes to respond to inquiries such as these: “You don’t need a noise control engineer, you need a real estate agent.”

3. – Juan Arevelo responded

White noise boxes won’t help because the vibrations are much lower in frequency. Such low vibrations have wavelengths comparable to the size of the rooms and home. Therefore, you’re dealing with resonance structural vibrations. If the main problem is the noise level itself, then I recommend to purchase a pair of noise-cancellation headsets. The best ones are from Bose for about $300. You will still feel the vibrations, but at least you may be able to sleep better. Another idea is to decouple the bed from the housing structure by placing low-frequency vibration damping material between the floor and legs of the bed. Some research is needed to identify the best material to do this, but I would start with rubbers.

Juan

Vibration and Noise Control Class Offered

Media Contact:
Carolyn Cordrey
(888) 501-2100
ATIinfo@aol.com

Vibration and Noise Control Class Offered

Respected specialists Dr. Eric Ungar and Dr. James Moore will be teaching Applied Technology Institute’s “Vibration and Noise Control” course in 2009. The four-day course focuses on vibration reduction and quieting of vehicles, devices, and equipment. It will provide guidance relevant to design, problem solving, and development of improvements. Dr. Ungar has served as president of the Institute of Noise Control Engineering, Chairman of the Design Engineering Division of the American Society of Mechanical Engineers, and has won awards for his work on vibrations of complex structures, structural damping, and isolation. Dr. Moore developed Statistical Energy Analysis models for the investigation of vibrations and noise in complex structures such as submarines, helicopters, and cars. He has participated in the development of active noise control systems, noise reduction coating, and signal conditioning means. Both have many years of teaching.

Dates and Locations: March 16-19, 2009 in Boston, MA and May 4-7, 2009 in Beltsville, MD

Dr Ungar has also published a humorous Acoustics from A to Z, that is available at

http://www.ATIcourses.com/sampler/Acoustics%20from%20A%20to%20Z.pdf

ATI is the leader in scientific and technical training since 1984. Regisration: call 410-956-8805 / 888-501/2100 or online at www.ATIcourses.com