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A couple reference requests, Help me find a few paper followups
xiphmont
post Sep 15 2013, 20:44
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Hi folks, I'm trying to tie up a few loose ends in my mental 'paper-trails'. These are all relatively unrelated requests, I'm hoping folks are able to point me to relevant papers as I'm oddly not getting anywhere with Google or AES search.

1) The infamous Oohashi: several people, AES and here, have mentioned failed attempts to reproduce the results in Oohashi _Inaudible High-Frequency Sounds Affect Brain Activity: Hypersonic Effect_. Until recently, I'd simply been under the impression no one had attempted to reproduce them. Does anyone have first-hand knowledge of a failed attempt, and even better, a pointer to a paper or three?

2) R Lagadec: Long ago, Lagadec suggested that frequencies above the last hair cell are perceived only as energy with without pitch or feature, and thus the best way to construct the AA/AI filter was with cutoff right at Nyquist and a transition band that purposely 'polluted' the area between 20kHz and Nyquist after folding, with extra points for choosing a topology that appeared to result in perfectly flat energy all the way to Nyquist after adding in aliasing. it seems that up until the early 2000s, this was the preferred method. Why exactly did it fall out of favor to be replaced my AA/AI filters that roll off much earlier and try to be 80-100dB down at Nyquist?

3) J Dunn: _Anti-alias and anti-image filtering: The benefits of 96kHz sampling rate formats for those who cannot hear above 20kHz._ A slightly different slant on a different effect measured by Lagadec, namely, equiripple AA/AI filters causing a pre-image of the sampled signal. An interesting idea and analysis save for the problem I've never measured the effect, perhaps because I've only tried to do so in modern ADC/DACs. Has anyone followed up this and other related papers with any sort of 'that was then, this is now' paper that establishes it as relevant only to an obsolete generation of technology? Or _are_ there modern samplers with the problem?

4) Ashihara: These papers, eg _Hearing thresholds for pure tones above 16 kHz_ interest me at the moment because they're plausible and fit preexisting evidence at first glance. I have a few worries about the specific methodology, but I don't know that I'm qualified enough to make a complex evaluation without additional experimentation. Of course, others may have done it, so I'm interested in followups and replication-- Of which I can find none, only citations using it as an authority. Any help?

Sorry for the unrelated topic spam list. Please... school me!
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Ethan Winer
post Sep 17 2013, 21:12
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QUOTE (xiphmont @ Sep 15 2013, 15:44) *
1) The infamous Oohashi: several people, AES and here, have mentioned failed attempts to reproduce the results in Oohashi _Inaudible High-Frequency Sounds Affect Brain Activity: Hypersonic Effect_. Until recently, I'd simply been under the impression no one had attempted to reproduce them. Does anyone have first-hand knowledge of a failed attempt, and even better, a pointer to a paper or three?

This paper refutes Oohashi et al, and also explains what was wrong with their test (using one tweeter to reproduce multiple ultrasonic tones):

http://www.aes.org/e-lib/browse.cfm?elib=10005

--Ethan


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I believe in Truth, Justice, and the Scientific Method
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