[another_someone]

Do deaf people get seasick?
If so then I think we can kiss goodbye to any idea that it's produced by infrasound (at least unless you can find another organ to sense the infrasound).
This page
http://www.royaldeaf.org.uk/page.php?id=100303
sugests that deaf peopel do suffer from seasickness.

I don't get seasick (or airsick or whatever) but I do get uncomfortable when there are high levels of low frequency sound- the ventilation system where I work sometimes has this effect.

I think infrasound can be detected away from the ear (in any case, it will depend on the nature of deafness, since I doubt it would effectively be channelled by the outer ear).

Don't forget that Beethoven could detect infrasound despite the deafness of his later years, and if you stand in a church with an organ playing its deepest notes, you will feel those notes right through your body, not merely through your ears (these notes do not normally record well on recordings of organ music, and that is the difference between listening to organ music live, and listening to a recording of it).

This is not to suggest that infrasound causes sea sickness (I never suggested that, only that it can induce drowsiness, and this has sometimes been claimed to be a factor in drivers falling asleep on long journeys).

[sgroclkc (OP)]

Motion sickness is caused by a kind of special, the low dull rumbling sounds.For example,we not get carsick can't hear this noise from the trains, subways, trucks, motorcycles, tractors

[Bored chemist]

Wow!
You came back after all this time, and ignored the evidence.

[sgroclkc (OP)]

Motion sickness is caused by a kind of special, the low dull rumbling sounds

[sgroclkc (OP)]

Carsickness is caused by the motor which produces a special and rumbling low-frequency noise. Train, metro, truck, motorcycle and tractor which produce no such noise will cause no carsickness.

[Colin2B]

Carsickness is caused by the motor which produces a special and rumbling low-frequency noise.

Motion sickness occurs without an engine.
Standard laboratory test to induce motion sickness is a standard office chair, subject blindfolded, chair rotated, subject told to put head back to side etc. Very rarely does this fail to bring on motion sickness. No motor.

Train, metro, truck, motorcycle and tractor which produce no such noise will cause no carsickness.

No so. I know people who suffer motion sickness on all of these.

If you have a theory of vibration induced sickness you need to clasify it as a separate theory from motion sickness.

[alancalverd]

For really good, violent and repetitive motion sickness, try glider aerobatics. No engine, and the better the glider, the less vibration at any frequency (noise and vibration = lost energy, and we don't like that!). It works best if you are in the front seat and the pilot  is behind you, so you have no visual cue as to what happens next. Those of a nauseous disposition can throw up when entering a very gentle turn, and even hardened powered aviators have a problem hanging on to their breakfast during a glider display sequence flown by the guy in the back seat.

Flying dual cross-country needs regular swaps between navigation and handling duties even in a side-by-side glider to avoid mal-d'air. Taking control gives you the cues you need to avoid eye/ear/brain confusion, which is why car drivers don't get sick when their passengers do. 

[sgroclkc (OP)]

Carsickness is caused by the motor which produces a special and rumbling low-frequency noise.

Motion sickness occurs without an engine.
Standard laboratory test to induce motion sickness is a standard office chair, subject blindfolded, chair rotated, subject told to put head back to side etc. Very rarely does this fail to bring on motion sickness. No motor.

Train, metro, truck, motorcycle and tractor which produce no such noise will cause no carsickness.

No so. I know people who suffer motion sickness on all of these.

If you have a theory of vibration induced sickness you need to clasify it as a separate theory from motion sickness.

The symptoms caused respectively by gyrating and carsickness are quite different. Gyrating movements will cause dizziness, while carsickness usually causes nausea or sleepiness. This is why authors of many scholar articles only state that gyrating symptoms are associated to carsickness, but the reasons behind carsickness are still unknown. Only unreliable knowledge popularizing articles say that the reason of carsickness is gyrating movements. This is not true. Actually, gyrating movements are not related to carsickness, which is actually caused by a special low-frequency noise. Only this kind of noise can cause exactly the same symptoms of carsickness. For example, even without staying on the airplane, the noise of airplane engine can also cause symptoms of carsickness. Experts of carsickness around the world all know that only noise can cause exactly the same symptoms of carsickness, but they fraud people by saying that this phenomenon is only a psychological reaction!

[alancalverd]

The stuff in my sickbags depends on what the victim had for breakfast, not whether the aircraft has an engine.

Part of the problem with instrument flying, yacht navigation or rear-seat car sickness is the inability of the semicircular canals to distinguish between linear acceleration and circular motion.    You can induce carsickness by stop-start driving on a straight road, and airsickness on scheduled flights or glider "dolphining"  is caused by sudden changes of pitch attitude, not turning.   

If it's all due to infrasound, why don't pilots and drivers suffer the same symptoms as their passengers? It isn't a matter of aptitude or experience - hardened drivers often throw up when navigating in rallies, and the most experienced pilots still need to swap duties with each other to avoid becoming incapacitated under competition conditions. 

The one time I had an entirely incapacitated crew was on a fairly large yacht, reaching  into an opposing tide. For about two hours, we made no progress over the ground but just pitched and rolled at random intervals in almost total silence, broken only by groans and the sound of eight experienced sailors donating their stomach contents to the sea. The only relief was to do something: taking the helm in turn, or tweaking the sheets, though the latter was completely unncessary as we had the boat pretty well trimmed anyway, but the feeling of being a bit in control or able to anticipate the next roll was very calming.

Early on in my sailing days I noticed an uncharacteristic craving for ginger biscuits. I later discovered that Chinese sailors have always used ginger as a prophylactic against seasickness, and it seems to work as well as modern molecules without inducing drowsiness. Any explanation would be welcome!

[jeffreyH]

Gingerols and shogaols.
http://www.sciencedirect.com/science/article/pii/S0031942215300509

[alancalverd]

Cool stuff, thanks.

Next time I do a glider aerobatic flight with a passenger, maybe I'll check the sickbag for curry residues. Or maybe not.

[sgroclkc (OP)]

The stuff in my sickbags depends on what the victim had for breakfast, not whether the aircraft has an engine.

Part of the problem with instrument flying, yacht navigation or rear-seat car sickness is the inability of the semicircular canals to distinguish between linear acceleration and circular motion.    You can induce carsickness by stop-start driving on a straight road, and airsickness on scheduled flights or glider "dolphining"  is caused by sudden changes of pitch attitude, not turning.   

If it's all due to infrasound, why don't pilots and drivers suffer the same symptoms as their passengers? It isn't a matter of aptitude or experience - hardened drivers often throw up when navigating in rallies, and the most experienced pilots still need to swap duties with each other to avoid becoming incapacitated under competition conditions. 

The one time I had an entirely incapacitated crew was on a fairly large yacht, reaching  into an opposing tide. For about two hours, we made no progress over the ground but just pitched and rolled at random intervals in almost total silence, broken only by groans and the sound of eight experienced sailors donating their stomach contents to the sea. The only relief was to do something: taking the helm in turn, or tweaking the sheets, though the latter was completely unncessary as we had the boat pretty well trimmed anyway, but the feeling of being a bit in control or able to anticipate the next roll was very calming.

Early on in my sailing days I noticed an uncharacteristic craving for ginger biscuits. I later discovered that Chinese sailors have always used ginger as a prophylactic against seasickness, and it seems to work as well as modern molecules without inducing drowsiness. Any explanation would be welcome!

It  was  firstly  proposed  by  a  Chinese  physicist  of  acoustics  that  motion  sickness  was  caused  by  infrasound.  After  reflecting  on  this  over  and  over  again  for  years,  I  think  this  view  is  wrong.  In  my  opinion,  motion  sickness  is  supposed  to  result  from  booming  low-frequency  noise.  For  instance,  it  is  beyond  doubt  that  extremely  loud  booming  low-frequency  noise  is  always  heard  inside  vehicles  which  easily  bring  about  motion  sickness.  Inside  vehicles  without  such  noise,  motion  sickness  isn’t  caused  at  all.  In  spite  of  loud  noise  of  tractors,  people  don’t  feel  sick  inside  them  because  there  is  no  booming  low-frequency  noise.  The  key  reason  consists  in  that  the  noise  of  tractors  doesn’t  distract  people  because  they  don’t  impact  their  verbal  communications  due  to  differences  between  frequency  of  the  noise  and  people’s  voices. 
     Some  other  evidences  can  prove  that  motion  sickness  just  arises  from  the  aforementioned  noise:  People  with  good  hearing  easily  suffer  from  motion  sickness,  while  the  deaf  and  dumb  who  can’t  hear  don’t  feel  sick  inside  vehicles  at  all.  The  noise  is  louder  inside  fairly  closed  vehicles,  so  people  easily  get  sick  in  highly  closed  luxury  buses  and  cars.  The  noise  is  so  penetrating  that  motion  sickness  can’t  be  avoided  either  even  if  ears  are  covered  with  something. 
        The  cause  of  such  amazing  trick  is  medical  experts’  lack  of  knowledge  about  acoustics.  They  have  only  noticed  that  the  tractor  doesn’t  cause  motion  sickness  although  it  is  rather  noisy,  so  they  have  wrongly  concluded  that  motion  sickness  doesn’t  result  from  noise.  In  fact,  they  haven’t  discerned  that  the  noise  of  a  tractor  differs  from  the  low-frequency  noise  which  brings  about  motion  sickness.  Although  they  couldn’t  figure  out  the  cause  of  motion  sickness,  they  were  too  hasty  to  reach  a  conclusion.  As  a  consequence,  they  have  scientifically  tricked  people  that  motion  sickness  is  associated  with  many  factors  such  as  shaking,  movement  and  visual  motion. 

[Colin2B]

Early on in my sailing days I noticed an uncharacteristic craving for ginger biscuits. I later discovered that Chinese sailors have always used ginger as a prophylactic against seasickness, and it seems to work as well as modern molecules without inducing drowsiness. Any explanation would be welcome!

Lots of sailors swear by ginger and interestingly NHS site recommends it for morning sickness. I've never found any firm evidence, some studies say it works others not. It's often discussed on sailing forums but seems to depend on the individual whether it works. It's a long time since I trawled the research, might have another look, if I come across anything interesting I'll let you know.
One thing most sailors will agree on is that getting your head down on a centre bunk really helps. Obviously there is less motion in the centre area and closing eyes removes the conflict , but I wonder whether the inner ear is more sensitive when head is upright than when prone.

[alancalverd]

Some  other  evidences  can  prove  that  motion  sickness  just  arises  from  the  aforementioned  noise:  People  with  good  hearing  easily  suffer  from  motion  sickness,  while  the  deaf  and  dumb  who  can’t  hear  don’t  feel  sick  inside  vehicles  at  all. 

Worth considering whether you are talking about profoundly deaf people or folk with normal neurology and anatomy but age- or noise-related deafness. Even age or disease can reduce one's propensity to mal de mer as the fluid in  the semicircular canals thickens. A friend of mine suffers from nausea with almost any change in position, due to deposition of calcite crystals in the canals - a fairly common and inherited condition -  which send multiple attitude signals to the brain.

Infrasound can indeed induce nausea, but the mechanism is thought to be different - either resonance in the chest cavity or disturbance of gut peristalsis. The human ear does not respond to sounds below about 15 Hz, which is why they are callled infrasound.   

[sgroclkc (OP)]

Wow!
You came back after all this time, and ignored the evidence.

The evidence show that people who gets sick in a car usually can travel in trains or motorcycles without any discomfort at all.

Why?

Low intensity infrasound from autocar engines has been well recognised to induce car sickness - a mild serotonergic-vestibular disturbance involving nausea, giddiness, headache.
https://www.quora.com/How-does-sound-hearing-influence-motion-sickness

[alancalverd]

The evidence show that people who gets sick in a car usually can travel in trains or motorcycles without any discomfort at all.

Why?

Because trains don't accelerate, decelerate and change direction as often or as violently as cars, and you turn a motorbike by leaning into the turn so you don't experience anomalous g-force and the passenger has a visual cue to the turn.  Plus the motorbike passenger is busy all the time, holding on and following the driver's lean, and can see where he is going.

[Colin2B]

The evidence show that people who gets sick in a car usually can travel in trains or motorcycles without any discomfort at all.

In addition to the post above which I agree with.
I know 2 pillion passengers who had to give up because of motion sickness. I also know people who can travel in a train if facing forwards, but not if facing backwards.
The only time I have felt motion sickness in a car was in the back of a taxi on one of the drop down rear facing seats.
Your 'evidence' is not empirically verified.

[sgroclkc (OP)]

Roaring low-frequency noise instead of infrasound causes carsickness. Symptoms of carsickness get stronger when vehicles bump or shake more frequently, which is just a coincidence. It is just because low-frequency noise gets louder when bumping and shaking gets more serious. Without such low-frequency noise, people will not feel carsick no matter how hard the car bumps or shakes. For example, people get carsick on trains or subways running at the same speed when hearing low-frequency noise. Without such noise on trains or subways, carsickness can be avoided. It fully proves that low-frequency noise is the only reason that causes carsickness.   
     By far, there has been no effective methods or progress to solve carsickness, as a result of false and deceptive carsickness theories brought up by authorities and experts. If people can acknowledge the view that low-frequency noise leads to carsickness, then they can immediately and completely get rid of carsickness, plane-sickness, or seasickness (part of seasickness is caused by low-frequency noise from storm at sea, which is unavoidable natural disaster) caused by low-frequency noise from the engine as long as all transportation tools stop generating such noises. It is readily feasible in terms of technology. Thus, if consumers purchase cars with loud noise, which is severe quality issue, they should immediately claim compensation from car manufacturers and require them to recall for remodeling until it stops making such noises in operation. Therefore, such noises will not only cause painful carsickness, but lead to hearing loss under long stimulation from such noises.

[Morgan IAT]

So how do things like 'facing forward' help reduce the effects of motion sickness?

[alancalverd]

(part of seasickness is caused by low-frequency noise from storm at sea, which is unavoidable natural disaster)

Never had a yacht crew be sick in a storm - too busy! But fishing with the engine shut down on a windless, silent, rocking sea, usually has everyone heaving up over the side. Good news is that this attracts more fish.