4 ms·
As a trained sound engineer, I don't find this explanation wholly plausible. Human hearing is increasingly less sensitive at low frequencies; the threshold of h
by jdietrich 7y ago
As a trained sound engineer, I don't find this explanation wholly plausible. Human hearing is increasingly less sensitive at low frequencies; the threshold of hearing is typically around 60dB at 20Hz and 72dB at 10Hz. Anyone who has configured a large public address system knows that vast amounts of power are needed to deliver useful response at these frequencies; many systems simply fake the presence of low bass by tuning in a big peak at 40 or 50Hz, which requires two or three orders of magnitude less power.
Structure-borne noise is a real problem in many buildings, but I'm aware of very few instances of neighbourhood-wide noise problems at very low frequencies.
https://en.wikipedia.org/wiki/Equal-loudness_contour https://en.wikipedia.org/wiki/Equal-loudness_contour
- blunte 7y agoI can’t say whether it is an ear hearing or some other sensitivity to resonance (of the skull?). The sensation is stronger on one side/ear, and it feels like the pressure you feel if someone goes “puh” softly in your ear in a quiet room... except that it happens over and over at a low frequency. I have experienced it in several different places. One place was at college on the cliffs overlooking the Mississippi river, and I suspect it was from the boats that push barges (cargo) down the river. Other places have been near heavy freight train routes, particularly when a train is idling somewhere within perhaps a mile. It’s like if a big truck is idling a few houses down the street in a quiet neighborhood. In one location in the mountains of Colorado, the sound could be heard a many locations throughout the valley. I know this because i drove around in the quiet and remote regions, stopping periodically to listen. Some spots were impressively loud, and others were not audible. In that environment I suspect it was due to wind over the mountain ridge (sharp edged on one side, and the wind would cause a pressure differential to build until it would break and the air would take a chaotic path briefly). This is similar to what you see and hear with a fireplace where the fire is burning mostly on one side of a log, but the air flows in a way that creates a pressure differential... and it may cause a puff puff puff pattern that is both audible and visible (flame leaping around the other side of the log exactly at the moment you hear the puff).
- specialist 7y agoTLDR: Please have your hearing thoroughly tested. I have no idea if this anecdote relates to your experience: My SO was hearing a rhythmic noise. More so at night. Very disturbing. Much drama. An audiologist (?) determined some of the tiny hairs inside one of the ears were flopping around. The supporting membrane got slack with age. A form of tinnitus. These tiny hairs are sensitive to motion, so even heartbeats and breathing will create the sensation of sound.
- blunte 7y agoWere there it not that my perception of the sound was highly dependent upon my location (even within one room), I might be inclined to believe it was my problem. If you’ve ever played with a good subwoofer, you know that where you stand relative to the speaker and the frequency it is generating greatly impacts your ability to hear it. You can be in a dead zone and hear almost nothing, but a few steps back or forward and suddenly your eyeballs are vibrating. Same thing with these environmental hum situations, but much more subtle.
- specialist 7y agoOf course environment & context effects hearing. Ears perceive changing air pressure as sound. The body feels other frequencies (whatever that's called). FWIW, my SO's perceptions varied with location as well. At the very least, an audiologist (?) would help you rule out factors. Or in our case, becoming more aware of the current best available science. Think of it as a physical. I certainly wish I had my hearing periodically thoroughly assessed. Like I already do for my pulmonary function, eyesight, BMI, etc. Also FWIW, even though my SO's condition is untreatable, awareness helped her better manage it. I hope you find some relief. Keep looking. Someone, somewhere has the answers you need. Best wishes.
- blunte 7y agoThanks. It's probably worth getting checked, because as you say it may help me understand how to manage things better. Fortunately it's rare that I'm in a location that's so bad for me that I can't handle it. The low-speed air purifier (fan) solution is usually good enough when necessary.
- egypturnash 7y agoI suggest you skim this: https://en.wikipedia.org/wiki/The_Hum https://en.wikipedia.org/wiki/The_Hum
- specialist 7y agoPlease see my other comment about undiagnosed tinnitus. I recently learned there are many different kinds. (Mine is from too much loud Drum & Bass.) My SO got obsessed with our local version of The Hum. Attending meetups, talking to strangers on nextdoor, letter writing, and so forth. While I have no doubt there are noises and other phenomenon that most people can't perceive, eg some animals seem to anticipate earth quakes, I prefer Occam's Razor more.
- stinos 7y ago60dB As trained sound engineer on HN, you sould use units which mean something, now you essentally just said '60 times more' so people will ask you 'more than what?' :)
- jdietrich 7y agoI would have thought that SPL is implied, given that no other unit would make sense in that context.
- stinos 7y agoYes, but I have the impression a lot of people who never came into contact with some kind of audio/hearing theory have no clue about that, so I think it is better to write it explicitly. Mainly because people who don't know what SPL means can just go and look it up, also learning comething, instead of remaining clueless and using dB as-is treating it as some absolute quantity.
- wool_gather 7y agoAs a trained sound engineer, you should know that the experience of low-frequency sound is not largely via the eardrum. The whole body is involved.