Inaudible High-Frequency Sounds Affect Brain Activity: Hypersonic Effect

ymir

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Fin påske litteratur :)


Inaudible High-Frequency Sounds Affect Brain Activity: Hypersonic Effect


ARTICLES | Journal of Neurophysiology


There are two factors that may have some bearing on this issue. First, it has been suggested that infrasonic exposure may possibly have an adverse effect on human health (Danielsson and Landstrom 1985), suggesting that the biological sensitivity of human beings may not be parallel with the “conscious” audibility of air vibration. Second, the natural environment, such as tropical rain forests, usually contains sounds that are extremely rich in HFCs over 100 kHz. From an anthropogenetic point of view, the sensory system of human beings exposed to a natural environment would stand a good chance of developing some physiological sensitivity to HFCs. It is premature to conclude that consciously inaudible high-frequency sounds have no effect on the physiological state of listeners.

Sound materials and presentation systems

Traditional gamelan music of Bali Island, Indonesia, a natural sound source containing the richest amount of high frequencies with a conspicuously fluctuating structure, was chosen as the sound source for all experiments. A traditional gamelan composition, “Gambang Kuta,” played by “Gunung Jati,” an internationally recognized gamelan ensemble from Bali, was recorded using a B&K 4135 microphone, a B&K 2633 microphone preamplifier, and a B&K 2804 power supplier, all manufactured by Brüel and Kjær (Nærum, Denmark). The signals were digitally coded by Y. Yamasaki's high-speed one-bit coding signal processor (United States Patent No. 5351048) (Yamasaki 1991) with an A/D sampling frequency of 1.92 MHz and stored in a DRU-8 digital data recorder (Yamaha, Hamamatsu, Japan). This system has a generally flat frequency response of over 100 kHz


To overcome this problem, we developed a bi-channel sound presentation system that enabled us to present the audible LFCs and the nonaudible HFCs either separately or simultaneously. First, the source signals from the D/A converter of Y. Yamasaki's high-speed, one-bit coding signal processor were divided in two. Then, LFCs and HFCs were produced by passing these signals through programmable low-pass and high-pass filters (FV-661, NF Electronic Instruments, Tokyo, Japan), respectively, with a crossover frequency of 26 or 22 kHz and a cutoff attenuation of 170 or 80 dB/octave, depending on the type of test. Then, LFCs and HFCs were separately amplified with P-800 and P-300L power amplifiers (Accuphase, Yokohama, Japan), respectively, and presented through a speaker system consisting of twin cone-type woofers and a horn-type tweeter for the LFCs and a dome-type super tweeter with a diamond diaphragm for the HFCs. The speaker system was designed by one of the authors (T. Oohashi) and manufactured by Pioneer Co., Ltd. (Tokyo, Japan). This sound reproduction system had a flat frequency response of over 100 kHz. The level of the presented sound pressure was individually adjusted so that each subject felt comfortable; thus the maximum level was approximately 80–90 dB sound pressure level (SPL) at the listening position


In conclusion, our findings that showed an increase in alpha-EEG potentials, activation of deep-seated brain structures, a correlation between alpha-EEG and rCBF in the thalamus, and a subjective preference toward FRS, give strong evidence supporting the existence of a previously unrecognized response to high-frequency sound beyond the audible range that might be distinct from more usual auditory phenomena. Additional support for this hypothesis could come from future noninvasive measurements of the biochemical markers in the brain such as monoamines or opioid peptides.
 

svart-hvitt

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ARCHIMAGO OM OOHASHI

"If you look around at audiophile articles, just like the Tannoy white paper, you will no doubt run across the "Oohashi Hypersonic Effect". Basically, this was a series of papers published at the turn of the Millennium by Tsutomu Oohashi and colleagues, some concepts initially discussed in an AES convention way back in 1991 before making its way to the Journal of Neurophysiology in 2000 with further additions. I'm not going to spend much time talking about this again because I have written and analysed the papers (including a more recent 2014 paper where the researchers used DSD128) back in January 2015's post "MUSINGS: What Is The Value of High Resolution Audio (HRA?)". The bottom line IMO is that this stuff is simply too speculative and clearly it's more complicated and should not be used IMO as proof that reproducing ultrasonic frequencies will always result in a beneficial effect. For example, the recent 2014 presentation actually considered safety issues and both "positive" and "negative" hypersonic effects on EEG activity were reported. My sense is that until there is actual paradigmatic understanding (not just observational reports of neurophysiological change), there is no point debating the Oohashi stuff as a pro or con. (For more on this along with links to other studies, including those that failed to replicate Oohashi, see the Wiki on "Hypersonic Effect")".

Archimago's Musings: MUSINGS: Do we "need" those >20kHz ultrasonic frequencies for high-fidelity audio?
Archimago's Musings: MUSINGS: What Is The Value of High Resolution Audio (HRA)?
 

ymir

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Archimago's Musings: MUSINGS: What Is The Value of High Resolution Audio (HRA)?


For your consideration, here's how I see it:

I believe the answer is clearly NO.

Bottom line: Before we accept theories

Hvordan han ser på det = fasit,absolutte sannhet?

Tro kan en gjør i kirken,så de som tror bør en holde seg unna sies det i enkelt miljøer,
spesielt hvis en attpåtil er klar i troen:rolleyes:

Before we = VI, er sikker menigheten?

osv,osv..


Det viktigste for meg var nå uansett dette,så da tilhører vel jeg den menigheten..og er godt komfortabel med det.

ARTICLES | Journal of Neurophysiology



None of the subjects recognized the HFC as sound when it was presented alone. Nevertheless, the power spectra of the alpha frequency range of the spontaneous electroencephalogram (alpha-EEG) recorded from the occipital region increased with statistical significance when the subjects were exposed to sound containing both an HFC and an LFC, compared with an otherwise identical sound from which the HFC was removed (i.e., LFC alone). In contrast, compared with the baseline, no enhancement of alpha-EEG was evident when either an HFC or an LFC was presented separately. Positron emission tomography measurements revealed that, when an HFC and an LFC were presented together, the rCBF in the brain stem and the left thalamus increased significantly compared with a sound lacking the HFC above 22 kHz but that was otherwise identical. Simultaneous EEG measurements showed that the power of occipital alpha-EEGs correlated significantly with the rCBF in the left thalamus. Psychological evaluation indicated that the subjects felt the sound containing an HFC to be more pleasant than the same sound lacking an HFC. These results suggest the existence of a previously unrecognized response to complex sound containing particular types of high frequencies above the audible range. We term this phenomenon the “hypersonic effect.”

God Påske ;)
 
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svart-hvitt

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Archimago's Musings: MUSINGS: What Is The Value of High Resolution Audio (HRA)?


For your consideration, here's how I see it:

I believe the answer is clearly NO.

Bottom line: Before we accept theories

Hvordan han ser på det = fasit,absolutte sannhet?

Tro kan en gjør i kirken,så de som tror bør en holde seg unna sies det i enkelt miljøer,
spesielt hvis en attpåtil er klar i troen:rolleyes:

Before we = VI, er sikker menigheten?

osv,osv..


Det viktigste for meg var nå uansett dette,så da tilhører vel jeg den menigheten..og er godt komfortabel med det.

ARTICLES | Journal of Neurophysiology



None of the subjects recognized the HFC as sound when it was presented alone. Nevertheless, the power spectra of the alpha frequency range of the spontaneous electroencephalogram (alpha-EEG) recorded from the occipital region increased with statistical significance when the subjects were exposed to sound containing both an HFC and an LFC, compared with an otherwise identical sound from which the HFC was removed (i.e., LFC alone). In contrast, compared with the baseline, no enhancement of alpha-EEG was evident when either an HFC or an LFC was presented separately. Positron emission tomography measurements revealed that, when an HFC and an LFC were presented together, the rCBF in the brain stem and the left thalamus increased significantly compared with a sound lacking the HFC above 22 kHz but that was otherwise identical. Simultaneous EEG measurements showed that the power of occipital alpha-EEGs correlated significantly with the rCBF in the left thalamus. Psychological evaluation indicated that the subjects felt the sound containing an HFC to be more pleasant than the same sound lacking an HFC. These results suggest the existence of a previously unrecognized response to complex sound containing particular types of high frequencies above the audible range. We term this phenomenon the “hypersonic effect.”

God Påske ;)
Hvis 100kHz var viktig for å forstå lyd, tror jeg temaet hadde fått større oppmerksomhet av flere kompetente lydfolk, både blant dem som ofte kalles praktikere og dem som kalles akademikere.

Nå har Oohashi holdt på med dette i 20 år uten at kompetente folk tar notis. Som inkompetent på lydområdet tolker jeg mangelen på interesse fra de aller fleste kompetente som en indikasjon på at teori (jf. konsensus om menneskets høregrenser) forklarer fraværet av interesse for høyttalere med kapasitet opp til 100 kHz i lydverden.
 

svart-hvitt

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Som inkompetent på lydområdet tolker jeg mangelen på interesse .
Er det mangel på interesse?
Det er mye interesse for 100kHz blant "audiofile", men nå snakket jeg om "de aller fleste kompetente [...] på lydområdet".

Jeg kan ikke se at 100kHz er et stort tema i akademia. Og jeg kan heller ikke se at kompetente høyttalerprodusenter legger så mye vekt på området over 22-25kHz.

Korriger meg hvis du mener jeg tar feil og du kan vise til eksempler fra akademia og høyttalerprodusenter på at 100kH vies stor interesse.
 

Hi-Fi akustikk

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Jeg kan ikke se at 100kHz er et stort tema i akademia.
100KHz er litt høyt, men ultralyd i kombinasjon med hørbar lyd er ganske hot. Så jeg tror du bør sjekke om igjen. Mye interessant innenfor nevro på dette temaet.

Du kan jo se på arbeidet til NPL f.eks.
 

ymir

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Det er da flere høyttaler konstruksjoner der diskanten strekker seg godt over 20 kHz,opp til 40 - 50kHz.
100kHz kjenner ikke jeg til,men syslet en tid med bånddiskanter til ett av Quad 57 parene jeg hadde.
Min erfaring tilsier at diskanten tilfører lyden positivt også nedover på samme måte som
en sub tilfører lyden (høyttaler) positive kvaliteter oppover i frekvens.

Det samme gjelder vel også pickuper som strekker seg godt oppover i frekvensområdet.
 

svart-hvitt

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Det er da flere høyttaler konstruksjoner der diskanten strekker seg godt over 20 kHz,opp til 40 - 50kHz.
100kHz kjenner ikke jeg til,men syslet en tid med bånddiskanter til ett av Quad 57 parene jeg hadde.
Min erfaring tilsier at diskanten tilfører lyden positivt også nedover på samme måte som
en sub tilfører lyden (høyttaler) positive kvaliteter oppover i frekvens.

Det samme gjelder vel også pickuper som strekker seg godt oppover i frekvensområdet.
Her er en kjent produsent som strekker den helt til 100kHz:

Reference One — TAD LABORATORIES
Compact Reference One — TAD LABORATORIES

Har hørt "Compact" og den var veldig bra (i mine ører).
 

ymir

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Inkompetente høyttaler produsenter?

IRS

15 Hz - 45 kHz

Artig lesing av testene av IRS att de hørte når det tapte enkelte diskanter.



https://www.lansche-audio.com/loudspeakers/plasmatweeter/


1.5kHz – 150kHz is remarkable!


coles 4001g super tweeter*-*Startsiden*søk

1.2 Khz - 35Khz,

Coles 4001G 16 ohm Super Tweeter, new 2016 manufacture stock. Used in Spendor BC1 & SP1, IMF, CambridgeR50, B&W DM2, DM2a, DM4, and in many DiY ...


http://www.monitoraudio.co.uk/products/platinum-ii/pl500-ii

22Hz - 100kHz


http://www.stereophile.com/content/...oudspeaker-specifications#YFWWPozUlowMWHpA.97


24Hz–40kHz



Kunne leitet opp flere inkompetente høyttaler produsenter,men her er da noen
 
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JENO

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Og på 99% av innspillingene er det ikke noe å hente over 20 kHz likevel, så hva er vitsen? Om det ikke er begrensning i mikrofonene, så er det gjerne begrensning et eller annet sted i elektronikkjeden. For ikke å snakke om den bortkastede lagringsplassen på ikke hørbar lyd.
 

ymir

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De faglige begrunnelsene er vel til syvende og sist ikke viktige.
Sluttresultatet derimot er viktig,som også med kabler;)

Noe av poenget i artikkelen er vel at selv om en ikke hører disse høye tonene så registrer hjernen disse lydene :rolleyes:
 
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