mhardy6647
Grand Contributor
- Joined
- Dec 12, 2019
- Messages
- 11,451
- Likes
- 24,863
tambour
Based on piecemeal knowledge and reading some isolated papers posted on audio forums, I would venture that the answer to this question is "yes".Do we process waves of sound, or time domain of sound?
It's right there in Lenhardt' s paper. He cites Maass's work from 1946 in the sentence just before the one I quoted:What do you mean? Is this Lenhardt's suggestion or yours?
In one of the earliest reports [4], the experimental work of Dr. Roger Maass performed in 1946 was cited. Maass, never credited again for his original discovery , made all the essential observations in regard to ultrasonic hearing phenomenology . Ultrasonic hearing was possible in humans but only by bone conduction.
The contents of the paper referred to by the OP are not plausible.
Better yet, you'd have to relate their method to actual normal listening. Those various Japanese papers tended to use methods that were rather, um, contrived.Actually, the frequencies mentioned in this paper match those referred to in a Japanese paper I read, where the result was that the ultrasonic frequencies from normal instruments were not heard or felt, but there was something about the Javanese gamelan providing some stimulation.
I'd have to look it up.
I don't understand why it would help with tinnitus though. On the other hand I've yet to find a really good description of how we process normal sound waves, and that would seem to be basic research that surely must be in someone's collection here?
I haven't been able to look for the paper I'm thinking of yet, I believe they used skin contact as well as listening in their test, and the results were quite specific. You're right about contrived methods, but they seem to be needed in this field sometimes... the problem with a lot of those Japanese papers is that nobody seems to be able to reproduce the results.Better yet, you'd have to relate their method to actual normal listening. Those various Japanese papers tended to use methods that were rather, um, contrived.
Lenhardt was writing about *bone conduction* btw.
I haven't been able to look for the paper I'm thinking of yet, I believe they used skin contact as well as listening in their test, and the results were quite specific. You're right about contrived methods, but they seem to be needed in this field sometimes... the problem with a lot of those Japanese papers is that nobody seems to be able to reproduce the results.
Tinnitus research is full of people looking for silver bullet solutions.
As for the link you gave, yet another description of "how hearing works" that cops out at the key point...
"The auditory nerve carries this electrical signal to the brain, which turns it into a sound that we recognize and understand.". What the brain does to understand sound is probably 90% of what we really need to know.
Audiology testing and research was concentrated on understanding only speech for a long time, and that is what is tested for in most hearing tests today: the easy route to understanding the brain, MRI scanning that has told us about so much else of what the brain does, is limited for hearing because you can't use high fidelity transducers (magnets and metal) and the environment is very noisy.
There will be good research out there, but a lot of noise as well, and hard for a lay person to pick out the nuggets, as it were.
That Japanese camp is alone in claiming that. It was started by Oohashi. Sorry to be short, but those exact claims have been discussed many, many times and the conclusion is that those papers have insufficient controls.Actually, the frequencies mentioned in this paper match those referred to in a Japanese paper I read, where the result was that the ultrasonic frequencies from normal instruments were not heard or felt, but there was something about the Javanese gamelan providing some stimulation.
I'd have to look it up.
I don't understand why it would help with tinnitus though. On the other hand I've yet to find a really good description of how we process normal sound waves, and that would seem to be basic research that surely must be in someone's collection here?
That's probably because the description isn't straightforward. It's a combo of the envelope, spectrum, timing between waves and periodic fluctuations.On the other hand I've yet to find a really good description of how we process normal sound waves, and that would seem to be basic research that surely must be in someone's collection here?
Says me. I'm no scientist, but none of the established science supports >20kHz hearing. What's that based on? The books I've read, what I understand of anatomy, etc. (On anatomy, Lenhardt says the cochlea/basilar membrane is sensitive to ultrasound is based on a calculation of where it could resonate. Conjecture with no supporting data.)Says who?
The paper is about "Ultrasonic Hearing in Humans: Applications for Tinnitus Treatment". It's a literature review. It has f-a to do with the home audio reproduction, the nominal topic of this forum, or the way we listen to audio from our system.
I see. I would not that have described that passage in that manner.It's right there in Lenhardt' s paper. He cites Maass's work from 1946 in the sentence just before the one I quoted:
The billboard uses technology manufactured by Holosonic that transmits an
"audio spotlight" from a rooftop speaker so that the sound is contained
within your cranium.
Odd you shpuld mention that: just today I was listening to a podcast talking about the beyond audibility of many hi-res specs, and the only material that could be reliably perceived as sounding different when fc was raised from 20 to 30kHz was weird music using gamelan triangles. Apparently they generate some bad-assed harmonics.Actually, the frequencies mentioned in this paper match those referred to in a Japanese paper I read, where the result was that the ultrasonic frequencies from normal instruments were not heard or felt, but there was something about the Javanese gamelan providing some stimulation.
I'd have to look it up.
I don't understand why it would help with tinnitus though. On the other hand I've yet to find a really good description of how we process normal sound waves, and that would seem to be basic research that surely must be in someone's collection here?
Sorry, but I am a pedant. Sometimes it's a strong point, sometimes not.Good grief. I pointed to the NIH/NIDCD site not to have pedants pick apart the text on a particular page, but to point up what should be obvious: the existence of whole realms of science that actually study audition. And yes, 'what the brain does to understand sound" is within the ambit of those realms....psychoacoustics, audiology, cognitive sciences, neurosciences, and other overlaps.... in science you don't get to decide 'what we really need to know' until first you familiarize yourself with what we *do* know.
Lenhardt was a leading researcher in hearing loss remediation for decades. There's no quackery about this.
Spot on. So what is the textbook for students on how the brain (ie. after the signal enters the auditory nerve) processes sound? I guess I'll have to start looking, something to do during the Christmas break apart from requiring some of my rudimentary guitar playing after a year with a bad shoulder...until first you familiarize yourself with what we *do* know.
Depending on what you want to cover, here are two:Spot on. So what is the textbook for students on how the brain (ie. after the signal enters the auditory nerve) processes sound? I guess I'll have to start looking, something to do during the Christmas break apart from requiring some of my rudimentary guitar playing after a year with a bad shoulder...
I would have thought that the cochlear can vibrate at ultrasonic frequencies as much as it likes, but if there are no hairs active at those frequencies nothing gets to the auditory nerve for normal hearing of those frequencies to take place. You'd need to establish some other route to stimulation of nerves for it to work.Plausible. Bone conduction works across the spectrum and when a tuning fork if alternately placed on the forehead (or mastoid process, the bump behind the ear at about 4:00) and near the ear and not touching anything, most people can hear through air for considerably longer than through the skull. For those with conductive hearing loss via the ossicular chain, bone detection becomes more sensitive than air conduction--or at least as how this is crudely measured. So yes, we hear through our skulls, even at relatively modest volumes when a vibrating object is in contact with the skull.
Nor am I or should anyone really be surprised that there is some ultrasonic portion of the cochlea. The part that seems a bit dodgy based on what is given is that ultrasonic stimulation may lead to a re-acquisition of some hearing in nearby frequencies via neural plasticity and adaptive changes.
Oh that and whales/dolphins, primates and bats all diverged very early in mammalian evolution at about 90MYA, and so not sure what the point was about detecting ultrasonic evolution other than its very much a property of skull anatomy and the way hearing apparatus is embedded in a bony structure surrounded by gelatin.
What is clear is that this gives more fuel to the bats in the belfry wing of audiophiliacs insisting on 40kHz reproduction, but hopefully leads to some therapeutic modalities for tinnitus.