A weird one - amps and nausea

[Mark Hammer]

Somebody on another forum posted this the other day: " I love my '66 Bassman, but it makes me feel very strange when I push it. Sure it's a loud amp, but I've got much louder that don't create this effect. Wonder if it could be the frequency of the amp's natural voice/EQ that makes me feel so woozy and disoriented. I've been to a few loud concerts that had the same result for a few hours afterward also (but then again, I've been to many more that didn't!). "

What I was wondering is if there existed some sort of aural analog to that phenomenon that happens when you're sitting in a bus or train station, and for a brief instant you can't tell if it's your bus/train starting to move or the one beside you. Not evertyone feels nauseous under those circumstances, but enough people do that it's a real thing.

In this instance, it's the ambiguity of what you see that is conflicting with your vestibular sense that creates the nausea. Is it possible that some amps might create very low-frequency sideband products that create ambiguity of pitch, or perhaps a combination of different speaker phases that produces a conflict between vestibular sense and perceived sound origin?

Just curious.

has anybody here ever experienced what the OP describes?

[Steve Conner]

Plenty of forum members seem to feel sick and disoriented when working on Mesa Boogies.

[Mark Hammer]

Well, a wee bit of poking around and it seems it's a real thing.

The Sonic Weapon of Vladimir Gavreau | Journal of Borderland Research

Low frequency nausea - diyAudio

Given that it is infrasonic sound that provokes the nausea, I'm wondering if it might be higher-ampliltude infrasonic stuff shaking up those little otoliths in the inner ear, resulting in a conflict between what your vestibular sense is telling you and what your eyes are telling you. Again, an aural analog of what happens in the bus/train station.

Hmmm, perhaps the cure involves cabs/speakers with a tighter bass rolloff, or maybe earplugs.

[Steve Conner]

Yup, the "brown note". Mythbusters did an episode on it and considered it busted, but they're not exactly known for scientific rigour.

Then again, neither is DIYAudio or the "Journal of Borderland Research".

[52 Bill]

I can remember going into a large high end department store in a mall and feeling sort of out of sorts. It didn't happen anywhere else in the mall and it would happen nearly every time I would walk into that store. I assumed that it had something to do with the frequency of the ultrasonic motion alarm sensors.

Although I guess that they could have been using an early version of the sonic devices to keep the riff raff like me out of their posh store.

[Chuck H]

I can remember going into a large high end department store in a mall and feeling sort of out of sorts. It didn't happen anywhere else in the mall and it would happen nearly every time I would walk into that store. I assumed that it had something to do with the frequency of the ultrasonic motion alarm sensors.

Although I guess that they could have been using an early version of the sonic devices to keep the riff raff like me out of their posh store.

LOL!

I think it's entirely possible. But I also think a small amount of this effect may not be a bad thing! After all, the intention is to provoke a response. Often a complex one. As an example... Why in the world would anyone eat chili peppers!!! I love them. I don't know why.

Point is... Sometimes a small amount of something foul can make the perfume smell irresistible! Why can't the same hold true for guitar tone? Mark may have stumbled onto one of the "secret ingredients".

[Enzo]

Oh wow, if a touch of foul helps, there is still hope for my playing.

Your department store could have an ultrasonic something, or it could go the other way, and the HVAC venting may have some infrasonic resonance.

It is one thing to propose there is some note that makes your ass vent, but it is another altogether to posit that notes that resonate in your chest might have an effect on you. You wouldn;t have to notice it directly, just a certain resonance might affect your lungs ability to move air efficiently, and you wind up tensing up.


Does it happen with this particular amp through just any speaker? Or only through a particular cab? And does the location matter? Oh,wait, it wasn;t you... never mind... I don't recall the thread, but it might also be possible there is some small ground current that is flowing through the player causing the distress.

[Steve Conner]

Another possibility... Mythbusters used a load of PA subwoofers. They stacked them in a circular array pointing inwards and put Jamie in the middle. I'm sure it was loud, but cone speakers are notoriously inefficient, so the acoustic output power may have been much less than in Gavreau's experiments. A 10kW stack of bass bins might only produce 100W of acoustic power. But then where does that leave a '66 Bassman?

[Mark Hammer]

One would be remiss in ignoring individual differences. There are folks who get carsick easily, and folks who don't, folks who curl up in a ball when they hear fingernails on a blackboard, and folks who don't, folks who get dizzy easily and recover quickly, and folks who don't. I have no problem with fingernails, but the sound of styrofoam being crushed is very tough on me. My son dug around and found that there are folks who, like him, get nauseous at the scent of coriander being chopped up. All "real things".

So, it's easy to imagine that some people do experience the sort of vestibular disturbance from louder low-freq content that I'm suggesting. It's a "real thing", just not real for everyone.

[Enzo]

Maybe it is just a Canadian thing.

[oc disorder]

I recall hearing about Hitler using subsonic generators at rally's prior to giving one of his stirring speeches.

When he started speaking it was turned off creating a feeling of well being amongst his audience.

I suppose this is similar to a main rock act choosing a dissonant support band !

After a quick search I have been unable to verify this so I'm not sure if it's the product of a fertile
imagination or something from sci-fi fiction !

[Steve Conner]

Doesn't matter if your information is accurate, you forfeited the debate by mentioning Hitler.
Godwin's law - Wikipedia, the free encyclopedia

[Mark Hammer]

Which raises the question, do folks south of the equator only get dizzy if they rotate counter-clockwise?

[Mark Hammer]

And of course, if you're not a particularly great headliner, you get Hitler to open for you....then a comedian....THEN you come on.

But more seriously, there ARE these things: Long Range Acoustic Device - Wikipedia, the free encyclopedia

...although the entry indicates they function at 2.5khz which is far from infrasonic.

[olddawg]

Sears used to do that to me back in the 70s. I was told it was the alarm system. I doubt if any of this is subsonic. It would require huge power and massive drivers. More likely ultrasonic. I've seen people react to cross phased horns and accidental just beyond the range of hearing oscillation in big bi and tri amped PAs before. And of course dogs go nuts. I could always tell when something was wired out of phase when you walk away from the stage and you can feel the interference pattern nodes as you cross them. I can see where some people could be sensitive to it.