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HUG - here for all audio enthusiasts

At its inception ten years ago, the Harbeth User Group's ambition was to create a lasting knowledge archive. Knowledge is based on facts and observations. Knowledge is timeless, independent of the observer and can be replicated. However, we live in new world in which objective facts have become flexible, personal and debatable. HUG operates in that real world, and that has now been reflected in the structure of HUG.

HUG has two approaches to contributor's Posts. If you, like us, have a scientific mind and are curious about how the ear works, how it can lead us to make the right - and wrong - decisions, and about the technical ins and outs of audio equipment, how it's designed and what choices the designer makes, then the factual Science of Audio sub-forum area of HUG is your place. The objective methods of comparing audio equipment under controlled conditions has been thoroughly examined here on HUG and elsewhere and can be readily understood by non-experts and tried-out at home without deep technical knowledge.

Alternatively, if you just like chatting about audio and subjectivity rules for you, then the Subjective Soundings area is you. If upon examination we think that Posts are better suited to one sub-forum than than the other, they will be redirected during Moderation, which is applied throughout the site.

Questions and Posts about, for example, 'does amplifier A sounds better than amplifier B' or 'which speaker stands or cables are best' are suitable for the Subjective Soundings area. From Oct. 2016, Posts in the Subjective Soundings area will not be spell checked or adjusted for layout clarity. We regret that but we are unable to accept Posts that present what we consider to be free advertising for products that Harbeth does not make.

The Moderators' decision is final in all matters and Harbeth does not necessarily agree with the contents of any member contributions and has no control over external content.

That's it! Enjoy!

{Updated Jan. 2017}
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Inaudible High-Frequency Sounds Affect Brain Activity: Hypersonic Effect

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  • Inaudible High-Frequency Sounds Affect Brain Activity: Hypersonic Effect

    Here is an interesting study from Japan that challenges the notion that inaudible sounds do not affect the acoustic perception of audible sounds.

    http://jn.physiology.org/content/83/6/3548.full

    Note: The authors use "HFC" to denote high frequency components of sounds, above the audible range, below 22kHz. "LFC" denotes low frequency components of sounds, below the audible range, above 22kHz.

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    "Despite the fact that nonstationary HFCs were not perceived as sounds by themselves, we demonstrated that the presentation of sounds that contained a considerable amount of nonstationary HFCs (i.e., FRS) significantly enhanced the power of the spontaneous EEG activity of alpha range when compared with the same sound lacking HFCs (i.e., HCS). In parallel experiments employing exactly the same stimulus and methods, PET rCBF measurement revealed that FRS activated the deep-lying brain structures, including the brain stem and thalamus, compared with HCS. In addition, subjective evaluation by questionnaire revealed that FRS intensified the subjects' pleasure to a significantly greater extent than HCS did. We conclude, therefore, that inaudible high-frequency sounds with a nonstationary structure may cause non-negligible effects on the human brain when coexisting with audible low-frequency sounds. We term this phenomenon the “hypersonic effect” and the sounds introducing this effect the “hypersonic sound.” We do not think that the hypersonic effect is specific to the sound material used in the present study because we previously confirmed, by EEG analysis, that the same effect can be introduced by different sound sources containing a significant amount of nonstationary HFCs (e.g., Oohashi et al. 1994)."
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