Mysterious noise keeps couple awake in their home - no source found!

[Elgin Clock]

http://news.yahoo.com/s/ap/20080723/..._mystery_noise

Any thoughts? I know we have a lot of people cruising these forums from a lot of different backgrounds & experiences.

Maybe one of us will have the answer or an idea what this mystery noise could be.

[artdutra04]

It's the MLB spying on them - they should coat their entire house with aluminum foil and metal coat hangers.

On a more serious note, it could be anything from water hammering in pipes in their walls, to anything with a motor, like their refrigerator, air conditioners, water/sump pumps, pool pumps, or a thumper built by a neighbor obsessed with Dune. Or depending on how close they are to a railroad, highway, power plant, water/sewer pump station, or any industry that uses diesel engines, if the wind is blowing just right, sound can carry on for miles. Or they have a wicked ground loop hum in any speakers they have in their house (which at 60 Hz, would probably sound like a low engine rumble).

Or they are just imagining it.

[MrForbes]

tinnitus?

I hear some interesting sounds coming from the overhead power lines when I go for a walk down the street.

[Koko Ed]

Who you gonna call?

[Madison]

Originally Posted by squirrel

tinnitus?

I hear some interesting sounds coming from the overhead power lines when I go for a walk down the street.

One of the ski resorts here, Stevens Pass, has several runs that keep alongside the high voltage power lines used to carry electricity over the Cascade range from hydroelectric dams in Eastern Washington.

Those lines make a deafening hum and my hearing is just fine. It's a bit surreal, actually, having to shout above the sound of electricity to get people to hear you.

[Al Skierkiewicz]

I have two possible causes. Invoking the Nottke Rule (named after a past co-worker) go where the last person was. i.e. the Church. We had a similar problem in my neighborhood after the library changed their air handlers. The high volume (6-8 ft diamter) intake fan (vaneaxial fan is the term I think) they used required a pillow block secured to top, bottom and sides of the intake duct. The installers placed the block supports too close to the blades of the fan and the resulting turbulence as a blade passed by the supports resulted in a "hum" that exceeded daytime residential acoustic standards by several dB. The closest house faced the intake about 100 yards away. Turning off the fan was not enough to stop the blades as air passing through the intake kept the fan turning enough to create the noise. (for a library it was neccessary to have high volume, low velocity, air) The shutters on the intake had to be closed before the fan would stop. Since the turbulence was on the outside of the fan assy, most of the noise went right out the intake. There was a little noise in the library.
Second possible occured in a recording studio out west. The owners decided to place the studio way out in the country where there were no airports or factories and the closest road was more than a mile away. To top it all off, when the core samples came back they found some sizable bedrock under neath the planned studio location. So the owners thought they would have no problem. After all the money was in and construction was finished they found a serious low frequency noise problem that couldn't be explained. Consultants were called in and during one of the investigations, the consultant looked out the window and noticed a big truck driving on the road in the distance. When the truck was gone, so was the noise. However, the truck was hauling rock from a nearby quarry. It turns out that the "rock" they had built on turned out to be just that, a large rock. One end came up under the road and the other end came up under the studio. Push on one side and the other side moves. In between the rock was below grade so no one thought there was a connection. It turns out that sound travels faster through rock than through air.

[Mike Schroeder]

while this really isn't related, It is still slightly on track

I work at Home Depot, I was a cashier for a long time. I was working the Returns Desk on night and a lady came in and told me she wanted to return a Carbon Monoxide Detector, I ask her the standard is there something wrong with it? she tells me its broken because she plugs it in and it starts beeping. I looked at her for a second and asked her if maybe she had a Carbon Monoxide problem. She said she was not sure and left with the Carbon Monoxide Detector in hand

[IndySam]

In my old condo once or twice a month I would hear a strange motor and vacuum noise that I couldn't figure out. After many months I finally discovered that is was a street cleaner that would clean the parking lot of the strip mall down the street.

And you should ask team 45 about the Kokomo Hum.

[acdcfan259]

Originally Posted by IndySam

And you should ask team 45 about the Kokomo Hum.

What, do the Beach Boys play for days on end?

Nobody.... I hate you guys.

[Travis Hoffman]

I think it's the C.H.U.D.'s trying to get out of the sewer....

[MikeDubreuil]

I can't believe they used tax dollars to investigate a problem at someone's private residence. The homeowner should pay for that- not the people of Green Bay.

[John Wanninger]

This situation might be a good application for using a sound intensity probe. Sound Intensity is "a time-averaged, directional quantity that measures the rate of energy flowing through a specified unit area." (See http://www.soundintensity.com/si_technical.htm) By measuring sound as a vector quantity and determining the direction of the sound energy (as opposed to just the sound pressure level), perhaps the source of the sound can more easily be located.

[Andy Baker]

Originally Posted by IndySam

And you should ask team 45 about the Kokomo Hum.

I worked with a guy at Delphi a few years back that was investigating the "Kokomo Hum".

There have been articles in the NY Times and ABC News.

He had two theories:
1. The Soviet communists were purposely trying to annoy us.
2. Alien lifeforms were invading us.

Well... he had other theories. There are 2 very large auto parts plants in the city. These other theories included industrial fans and power sources for these plants. However... he did actually talk about aliens and commies.

Food for thought. Maybe my former co-worker moved to Green Bay.

AB