DocNoise · HackerTrans

I love you humor... this sort of logic could be expanded to basically everything mankind invented since we climbed down from the trees ;-) ...Shoes! Consider how deadly the are to ants! ... Soap! Consider how deadly it is to microbes! ... Nah, seriously: It's a matter of design. Cars don't need to harm the environment and they don't need to be noisy or overly dangerous. The problem is inconsiderate pea-brained idiots that don't think of others - and noise regulations that lag behind what's known in the scientific community by decades.

DocNoise

7 anni fadiscuss

Wait. I need to answer your question properly on a physiological level as well: The problem is that LFN signals that reach the inner ear get sent to the brain on 3 separate channels, with a signal from the otolith organs going to the vestibular nuclei and finally also to areas that regulate autonomic functions. As it seems, these effects show a much lower ability to adapt to "noise" in the broadest sense.

DocNoise

7 anni fadiscuss

Well, a certain level of habituation can sometimes be seen - especially when the exposure isn't constant and the level is rather low. But the process can take years and is influenced by many factors. If sleep quality is good and blood pressure & cortisol levels are ok, one might consider "waiting it out"... if secondary effects increase, additional stress sources (job) pop up or relationship trouble starts, moving might be the smartest option. Another way would be to do a survey in the neighborhood and if other people are affected, collecting some money and hiring a acoustician with a proven track record of solving LFN cases to find the source. Once the source is identified, searching for a solution would be the next step. Sometimes simple things like swapping a fan in an air chiller can make a huge difference.

DocNoise

7 anni fadiscuss

It is important to stress that the mechanism described are completely disconnected from so-called psychological aspects "personality traits" and general sensory processing (like falling into the HSP definition). Elaine Aaron's work is remarkable from a scientific standpoint but should also encourage people to pay more attention to the type and amount of external stimuli we expose ourselves to.

The effect of being unable to follow a conversation in a noisy environment however, IS a solid indicator of the processes I describe (you might want to look up "hidden hearing loss" - Kujawa & Libermann have published on this phenomenon).

DocNoise

7 anni fadiscuss

Most of what I am writing is pretty basic otoneurological knowledge. Researchers like Bohne, Harding, Dallos, Salt, Lichtenhan, Hudspeth, Moller, Kugler, Drexel et al. have published extensively on this issue. Some links to peer-revieved literature are listed in my Stackexchange post.

DocNoise

7 anni fadiscuss

Just realized that Stackexchange is currently showing only an abridged version of my blurb on the question of "adaption to LFN (low frequency noise)", so I paste the long version below. Links to literature can be found in my other post(s). I don't cover the involvement of the otolith organs (yet) but that's your connection of a low-frequency sound stimulus to the sensation of (whole body) vibration, dizziness, balance problems, blurred vision, changes in peripheral blood flow and breathing problems.

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Very quickly and totally from the top of my head: Traffic noise is in many cases dominated by low frequencies, with the whole spectrum somewhat similar to a distorted 1/f function, with a few tonal peaks for exhaust noise and tyre/tread sounds. Now add the structure you are living in: "excellent sound insulation" in the EU is (still) dB(A)-focused, meaning architects and planners are aiming for a "wow" effect in noise reduction by eliminating that what's easy to eliminate - high and mid frequencies, ignoring mostly the low (and energy-rich) frequencies, which are incidentally the ones the A-weighing of noise is (historically) ignoring as well. As a result, you are basically living in what's known as a low-pass filter, one that is also "drawing" tonal peaks (resonances, room nodes) out of that low-frequency noise mixture. At first, your cochlea's short-term adaption mechanisms will do their job well and tone down signals that are not meaningful (MOC reflex). Over time however, the presence of low-level tonal, continuous sounds can damage ("wear out") a specific sensor type necessary for this reflex to work. As a result, even inaudible LFN noise can, over time, lead to a distal sensitization effect. In many cases the culprit is actually not the traffic noise itself, but HVAC installations like heat pumps, A/Cs and gas turbines. The effect of "I can hear too much" (being aware of noises) as a result of sub-threshold LFN-exposure is known in the medical literature as a symptom of VAD stage I / II and in fact quite common in the urban population. Certain medications (Gentamycine, cis-platines) as well as organic solvents (acetone) and some disinfectants can speed up this process, which is non-reversible and poses a risk factor for suffering atypical (early onset) hearing loss later on... The "I hear too much" effect has been quite a solid indicator of long-term, low-level IS/LFN noise pollution. To be on the safe side and to rule out a sub-threshold LFN-problem, you should an have an acoustician do a "LCeq-LAeq" (should not be more than 3-4dB) and an unweighted (FFT) spectrogram to see if there is a constant tonal peak below, say, 50Hz. Also, try to wear good earplugs like UVEX Whisper or UVEX Whisper Plus at night until you can rule out any constant / nocturnal IS/LFN immissions into your place.

DocNoise

7 anni fadiscuss

There is a difference between "being able to hear" very low frequencies and a situation where the inner ear has been sensitized - in many cases through a continuous LFN immission that's slightly below the average hearing threshold. If the exposure is constant, the dampening mechanism that is managing the adaption of the cochlea to sound of various intensities can "wear out" on a cellular level and the ear is basically reverting back to it's original (= super sensitive) state. The process of sensitization can also be accelerated/caused through the presence of ototoxic substances like certain organic solvents, desinfectants or antibiotics. Persons with this type of cochlear damage will experience a tiny low-frequency tonal peak in an otherwise "normal" sound spectrum as almost painfully loud, booming (spread out in frequency) and/or as a pressure on the ear. This damage will not show up in standard hearing tests, in fact, pure-tone audiometry will show above-average results. Currently, only DPOAE testing could in theory reveal this type of (rather common) cochlear damage in a non-invasive way. Even though not totally understood, there is epidemiological evidence that this type of aural sensitization is connected with (read: the cause of) disrupted sleep, higher cortisol levels and thus a heightened risk of infections, cardiovascular disease. The lack of sleep frequently leads to depression and anxiety disorders. ... more here: https://biology.stackexchange.com/questions/30101/do-our-ear...

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