See full version: Ultrasonic Waves Are Everywhere. Can You Hear Them
Back in the late 1960s and early '70s, researchers for the first time systematically examined what sort of sounds could cause problems in the workplace but were high-pitched enough that they didn't become problematic in limited, low-volume doses. Based on those studies, governments around the world arrived at a common guideline for ultrasonics in the workplace: 20 kilohertz at medium volumes, or 20,000 vibrations per second.
"If you're in the zone [of an ultrasonic sound] and you're one of the sensitive people, you'll get headaches, nausea, tinnitus [ringing in the ears] and [various other symptoms]," Leighton said. "And once exposure stops, you recover. After about an hour, you get better."
That's a very high-pitched sound — much higher than most adults can hear. In the video below, a tone slowly rises from a superlow 20-hertz tone to a 1,000-times-higher 20 kilohertz. I'm a 26-year-old man, and I can't hear anything once the tone rises past about 16 kilohertz. (But I can't say for certain that this isn't the result of my headphones maxing out, rather than my hearing.) [links]
"Or," he added, "a grandmother with a baby in her arms can walk into a public place where there's a lot of ultrasonic exposure, and the baby will be perturbed, and the grandmother will have absolutely no idea anything's going on."
"These are places where you might have a footfall of 3 [million] or 4 million people a year," he said. "So it dawned on me that we were putting ultrasound into public places where a minority but a large number of people are going to be affected." here
I purchased (Virtins) software pro version . it includes a Spectrum Analyzer and an Oscilloscope with bandpass function, all of it on your computer. The software can be used to analyze the WAV file recorded on the recorder. [links]
Vibrations must be caused by a source of energy. Your home has at least some of these types intentionally coming in: more
At the same time we had to get our shower replaced and ended up withwater hammer, with pipes banging every time we turned tap or shower off. This was sorted by draining down the systm but the stop valve leaked for while after obviously not being used for years. I read about the possibilty of worn/loose washers causing a humming noise but it sounds no louder when right beside stop tap. Hhhmmmm.
Any theories. What can I try?
I would suggest figuring out the frequency. This can probably be done using an application that will measure and name the musical note or a microphone plugged into an oscilloscope. Maybe there is an oscilloscope ap or musical note ap your phone could use. more
What can this be? Is it possible for gas lines to vibrate? Could it be a mains water issue? Someone suggested we could have a leak? Electrical problem (but had mains off and could still hear it)? Boiler issue?
Down the platform, a group of transit workers were not plugging their ears; most were wearing protective mufflers, the heavy-duty kind commonly worn by airport workers.
New machines were used to make sure trains' steel wheels were straightened, or ''trued,'' so they would roll without scraping. Wheels were fitted with stainless steel hoops to muffle ringing noises, in the same way a hand placed on a bell blunts the sound. Resilient rubber pads were installed beneath nearly all elevated rails and many underground rails, to quiet rumbling by reducing the vibration transferred to rails and trestles.
But now, he says, the issue seems to have fallen from the civic radar, he no longer has the energy to fight New York City Transit, and the tracks near his house, hushed for a while, are once again waking him up at night. more
WILLIAMSBURG — They got the message loud and clear.
The citywide ferry run by Hornblower started using the new horns over the weekend, according to Joshua Knoller, a spokesman for the company.
Marios Koufaris, 46, a waterfront Williamsburg resident, who'd earlier described the shrill ferry horns as the kind of sound designed to elicit panic, said he'd noticed lower-pitched and more muted horns over the weekend. more