FiDef and the Future of Music

– by Dustin Hackworth & Jayce Tomlin

FiDef has turned to the global front to ensure student projects from around the globe meet the highest standards for audio quality.  Using FiDef, educators are further expanding their range of flexible and creative options for students, creating the world’s most dynamic and comprehensive programs for music.  We’re excited to continue our efforts, hear from students and educators below!

Hear from a graduate of The Brit School for music

Nicola Thoms is a singer/songwriter based out of East London. Offered a spot at the Brit School of Performing arts at 16 years old, she quickly dove into the fundamentals of music and singing.  Since then, she has earned a degree in music and has been putting out singles and playing gigs solo and with bands.  She’s gained popular support from other artists and producers along the way, allowing her to go on tour in various parts of Europe.  Nicola releases all her music in FiDef.  Click here to listen.


Hear from a graduate of Berklee California

Warren Thomas Fenzi is a singer/songwriter based in Minneapolis, MN.  He also plays in Lucid Vanguard and 26 Bats!  Having attended Berklee College of Music in California, Fenzi knows all about what it takes to record a successful album a write a great song.  Warren is constantly gigging in the midwest and releases new material on a regular basis.  Warren releases all his music in FiDef.  Click here to listen.


Hear from the head of ICMP

ICMP London(Institute of Contemporary Music Performance) is a Music education provider located in London, UK. Started in 1985 by session Guitarist Alan Limbrick.  ICMP now focuses on providing education in areas such as songwriting, vocals, drums, music business, and music production. Students at ICMP use FiDef to bring their listeners closer to what their hearing in the studio.  We’re excited to continue to work with ICMP Director Pete Whittard and the burgeoning musicians at ICMP!  Click here to learn more.

FiDef has allowed musicians and students to amplify their studio performances and bring listeners closer to hearing what they intended.   Instructors at these institutions can also feel satisfied knowing that their students are working with the most cutting-edge audio tools. FiDef ultimately makes teaching, learning, and creating easier.  Get ahold of us at for more information on how you can get FiDef at your school.

The Hypersonic Body Buzz – Dr. Roger Dumas

Dr. Roger Dumas – Your Brain Hears More Than You Think Blog


20k – 20kHz – 20 kiloHertz audio frequency – 20,000 cycles/second  (the scientifically-accepted upper limit of human hearing)

Alpha-EEG – neuron populations firing at frequencies between 7.5Hz and 12.5Hz

CLL – comfortable listening level

EEG – electroencephalograpy

FRS – full range sound (HFC + LFC)

HFC – high-frequency component (above 22kHz)

IRB – institutional review board

LFC – low-frequency component (below 22kHz)


Previously on YBHMTYT (Your Brain Hears More Than You Think), you were presented with evidence that humans respond to sound waves at frequencies up to 50k Hz. According to researchers at ATR:

from ‘Inaudible high-frequency sounds affect brain activity: hypersonic effect.’

“Although it is generally accepted that humans cannot perceive sounds in the frequency range above 20 kHz, the question of whether the existence of such ‘inaudible’ high-frequency components may affect the acoustic perception of audible sounds remains unanswered. In this study, we used noninvasive physiological measurements of brain responses to provide evidence that sounds containing high-frequency components (HFCs) above the audible range significantly affect the brain activity of listeners.

“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.” (Oohashi 2000)

That last bit intrigues. If you were one of ATR’s business partners and you got the good news that people turn music up when it’s hypersonic, wouldn’t you pony-up for another neuroscience study? You bet you would. In 2006, the research team was given a green light to take the hypersonic effect to the next level. Their experiment design discussion might have played out like this:

Principal Investigator: “Okay. We know that people respond to above-20k music.”

Grad Student: “They not only respond, they appreciate it more. We know this because they’ll turn up the volume for hypersonic music.”

Post-Doc: “Also, we’ve seen a significant difference in alpha-EEG signal (7.5-12.5 Hz) for brains exposed to hypersonic music as compared to silence or standard music. That means the effect is real.”

PI: “But since the human auditory system seems to have adapted to use only frequencies under 20k, how are people getting hypersonic information?”

GS: “Gotta be biological.”

PD: (snickers) “Uh, yeah. That’s like, from the Journal of DUH.”

PI: “Now, now, GS has a point. How can we test it.”

PD: “Well, I suppose we could take ears out of the equation, like make the subjects temporarily deaf or something.”

PI: “I’ll never get that past the IRB. Not even gonna try.”

GS: “But couldn’t we isolate the ears from the rest of the body somehow? Give two presentations, ears only or full body for hypersonic or regular music.”

PD: “Yeah, and we could cover-up the body for some of the trials.

PI: “Now you’re talking! We’ll split the high and low components like we did before, but we’ll play them through speakers and/or earphones with the body exposed or covered. We’ll run ‘em through the EEG and behavioral task. Let’s do it!”

Which leads us to today’s review. Please note – all images in this article were fabricated by the author from freely-available resources. No copyright holders were harmed.


Biological Mechanism of Perception of Inaudible High-frequency Component Included in Music Sounds, Oohashi T., Nishina E., Kawai N., Honda M., Yagi R., Morimoto M., Nakamura S.,  Maekawa T., Yonekura Y., Shibasaki H., The third International Symposium  on Traditional Polyphony. (Tbilisi, Georgia, Sep. 2006)


“We showed that sounds of various traditional polyphony including Kartuli Pholyphonia and various ethnic musical instruments contain inaudible high-frequency component of air vibration above human audible range with conspicuous, non-stationary fluctuation in a micro temporal domain of the order of  millisecond. Using a cutting-edge scientific approach, we discovered that inaudible high-frequency components with complex structure activate the reward-generating neuronal system in the brain and make the musical sounds more comfortable to hear. We have called these phenomena collectively “the hypersonic effect.” It remains unclear, however, how such inaudible high-frequency components are transduced and perceived by listeners. We have recently succeeded in showing that inaudible high-frequency components of air vibration are perceived via some unknown sensing mechanism situated on the body surface, not via conventional air-conducting auditory system through ears. In this paper, we report the detail of this finding.” (Oohashi 2006)


Neuroimaging. Human brain activity was measured with electroencephalography (EEG) across 12 scalp sites during exposure to a super-audio CD (SACD) recording of Gambang Kuta, an Indonesian folk tune performed by the internationally-known gamelan orchestra Gunung Jati. (This is the same stimulus used in Oohashi 2000.)

Behavioral measurements. Subjects also engaged in a behavioral task during each trial, which was to adjust the music loudness to a comfortable listening level (CLL) using an up-down switch to operate a motorized fader between the SACD player and a pre-amp.

Stimulus. Capturing and playing hypersonic music is easy, especially if you own a proprietary high-speed one-bit coding signal processor with an A/D sampling frequency of 3.072 MHz like the Authentic Signal Disc ARHS9002 and Authentic Hypersonic Sound System (Yagi et al, 2002). As before, the signal was split into two bands, everything <22k and everything >22k (Fig. 1).

Figure 1. Frequency/amplitude chart for hypothetical hypersonic music sample split at 22k Hz.  FRS, full-range sound; LFC, low-frequency component (blue waveform); HFC, high-frequency component (red waveform).

Conditions. Now that they had the signal split, investigators could present three different stimuli (FRS, LFC and HFC) under three conditions (earphones, speakers with subject’s body exposed, speakers with body covered). The subsequent four sub-experiments chosen are explained in Table 1 and Figure 2.

Table 1. Table of 3 stimuli and 3 presentation conditions. For each treatment, LFC and HFC were played either alone or together during different trials.

Figure 2. Four treatments. (a) Both LFC and HFC presented through speakers; (b) Both LFC and HFC presented through earphones; (c) LFC presented through earphones, HFC presented through speakers; (d) LFC presented through earphones, HFC presented through speakers but with sound insulators preventing exposure of the subject’s head and body surface to HFC.


Neuroimaging. Alpha-EEG was significantly greater for FRS (as compared to LFC alone) when HFC was played over speakers (Fig 3a and 3c). When the subjects’ bodies were covered, alpha-EEG power was significantly diminished (Fig. 3d).

Behavioral. Measurements of subject behavior paralleled EEG results. Subjects usually adjusted loudness to significantly higher CLLs during FRS when HFC was played over speakers (Fig 3a and 3c). Conversely, subjects set CLLs at similar levels when during FRS when HFC was played through earphones. When a body surface was insulated from HFC coming through speakers, CLL was much lower.

Figure 3. EEG results across four treatments (LFC and HFC played simultaneously). a) FRS over speakers, b) FRS through earphones, c) LFC-earphones/HFC-speakers, body exposed, d) LFC-earphones/HFC-speakers, body covered. Subject images scaled to reflect overall alpha-EEG power levels.

Take-home message

The hypersonic effect is real, but it only works over speakers. And although this study shows that listeners tend to crank it up when hearing hypersonic music, subsequent research established that listeners could hear no qualitative difference between enhanced SACD and standard CD formats at normal listening levels. That finding might have dampened enthusiasm for marketing hi-res music to a general audience, but one can still purchase SACD players and find tons of great music on SACD.

And anyway, as Duke Ellington tells us, “If it sounds good, it is good.” You like it? Play it.

Next time, let’s talk about how your brain lives in the past.



Oohashi, T., et al.  (2000). Inaudible high-frequency sounds affect brain activity: hyper-sonic effect. J. Neurophysiol,  83:3548-3558.

Oohashi T., Nishina E., KAWAI N., Honda M., Yagi R., Morimoto M., Nakamura S.,  Maekawa T., Yonekura Y., Shibasaki H., Biological Mechanism of Perception of Inaudible High-frequency Component Included in Music Sounds, The third International Symposium on Traditional Polyphony. (Tbilisi, Georgia, Sep. 2006)

Yagi, R., et all. (2002) Auditory Display for Deep Brain Activation: Hypersonic Effect. In: The 8th International Conference on Auditory Display . (pp.248-253).

How High Can We Get? – Dr. Roger Dumas

Dr. Roger Dumas – Your Brain Hears More Than You Think Blog

Common misconceptions
An awful lot of Europeans living in the 1700’s were dead certain that eating tomatoes was what killed wealthy aristocrats. The actual cause of death was poisoning from lead leached out of pewter plates in contact with tomato juice acid, but that fact eluded most folks for a long time.

Similarly, you may know many things. Until just a few seconds ago, you might have known that many cognitive functions like speech, math, music, and creativity take place exclusively in your brain’s left or right hemisphere. In truth, this stuff happens all over the brain. In the same vein, you also know that machines will never outsmart people, that humans are the dominant lifeform on this planet, that you have consciousness and that people can’t hear sounds above 20kHz. Dog whistles, dolphin dialogs, bat bitch sessions, way over our heads. If I can’t perceive a signal, it doesn’t affect me and I don’t need it. Done.

But what if sub-audible sounds actually do do things to your brain? Might be nice to know. Maybe we could use the information to improve our lives, enhance music, clarify communications, things like that.

Well, it turns out that plenty of folks are looking into it. A research team based in Kyoto used neuroscientific and psychological methods to divine the answer to this question:

“Does music containing high-frequency components above the audible range significantly affect the brain activity of listeners more than music without high-frequency components?”

(Spoiler: They put the answer in the article’s title, but let’s dig into it anyway. Might learn something.)

Warning: The crude images you are about to see are shockingly amateurish artist’s conceptions. You might find the full-text version of this paper with original images right here


Inaudible High-Frequency Sounds Affect Brain Activity: Hypersonic Effect.
Oohashi, T., Nishina, E., Honda, M., Yonekura, Y., Fuwamoto, Y., Kawai, N., … Shibasaki, H. (2000). Journal of Neurophysiology, 83(6).


20k – 20kHz – 20 kiloHertz audio frequency – 20,000 cycles/second
(the scientifically-accepted upper limit of human hearing)

HFC – high-frequency component (above 20kHz)

LFC – low-frequency component (below 20kHz)

FRS – full range sound, HFC + LFC

HCS – high-cut sound (LFC)

LCS – low-cut sound (HFC)

FFT – fast Fourier transform

EEG – electroencephalograpy

Alpha – brain signal oscillating at 7.5Hz – 12.5Hz

Experiment #1 – Method

While EEG signals were acquired from their brains, 11 human subjects heard two different treatments of an entire 3:20 minute recording of “Gambang Kuta”, an Indonesian folk tune performed by the internationally-known gamelan orchestra Gunung Jati. The researchers recorded the ensemble using a crazy, one-bit high-speed digital system that captures a signal that’s extremely flat, reportedly out to 100kHz, or 80kHz higher than necessary for the modern ultimate musical experience.  

After they filtered the top-end off the full-range recording, they had 2 stimuli:

  1. FRS – full range sound, HFC + LFC, all frequencies
  2. HCS – high-cut sound (LFC), only frequencies below 20k.

I know, it’s a bit confusing. S’okay. We’ll just refer to the FRS as all-freqs and the HCS as lo-freqs. Here are my mock-ups of the FFT’s for the audio spectra for both stimuli. The all-freqs music is the super-duper, full-range sound straight from the recorder. The lo-freqs music is the same recording but rolled off at 20k, just like all the recorded music you hear every day.

Experiment #1 – Procedure

Subjects were asked to close their eyes and enjoy the music. Stimulus block design was silence, all-freqs, lo-freqs, all-freqs, lo-freqs, silence and the subjects heard this same block twice. (The lack of randomness in the presentation raises questions about sequence effects, but let’s give them a pass on this quibble.)

Experiment #1 – Results

The team found a significant difference in the alpha-EEG signal (7.5-12.5 Hz) for brains exposed to all-freqs when compared to silence or lo-freqs. They coined the term hypersonic effect to describe the phenomenon.

Figure 2. Artist’s conception* of alpha-EEG intensity plots for brain response to three different stimuli. Although subjects could not report having heard the higher frequencies in the all-freqs music, their brains lit-up dramatically in the parietal-occipital lobes (deep purple).

*An idealization, just like every exo-planet you’ve ever looked at online.

Another fascinating outcome was the discovery that hypersonic effect is integrated over time. Their subjects’ brains didn’t change in just a few seconds – the effect took hundreds of seconds to show up. Notice in Figure 3 how long it takes the hypersonic effect to go away after the all-freqs stimulus finishes.

Figure 3. Alpha-EEG intensity plots over time. (Artist’s imagination)

Experiment #1 Conclusions (mine)

If our bodies really do experience hypersonic effect, somebody might make a killing by re-tooling lo-freq audio technologies. Not surprisingly, this study was funded in part by the ATR Human Information Processing Research Laboratories, a cooperative effort between Japanese universities, private industry and government.

The ramifications for music enjoyment, telecommunications, hearing assistance and surveillance could be, well, huge.

But will we be enjoying 100kHz audio in our lifetimes?
In the next episode of Your Brain Hears More Than You Think, we’ll revisit Inaudible High-Frequency Sounds Affect Brain Activity: Hypersonic Effect and look at Experiment #2’s psychological survey concerning the pleasurability of hypersonic effect. We’ll also delve into a parallel study presenting the notion that it’s not your ears, but rather your body surface that picks up hypersonic sounds.

What now? Stay tuned.,

Your Brain Hears More Than You Think – Dr. Roger Dumas

Dr. Roger Dumas – Your Brain Hears More Than You Think Blog

To begin with, any stereo recording is a one-dimensional re-creation of humans performing in 3D. In a typical recording session, mics are placed in close proximity to sound sources. During the mixing stage, these monophonic signals are amplified differently on the left and right. When you listen through earbuds, you defeat your head-related transfer function. Consequently, your brain forms an impression of sound sources placed at various points along a line inside your head between your ears.

With headphones on, the sonic model breaks down; you’re not even getting two dimensions out of three!

What you hear is one-dimensional, but the original performance in 3D includes reflections and resonances off the floors and walls, every surface, including the performers and their instruments, like this:

Ok, so, sonic nuances can’t be captured in the recording process, so what?

Enter: lossy compression 

Without it, you couldn’t easily carry around thousands of tunes or download them from the cloud.   Mp3’s use “perceptual coding” to compress the data to make the most efficient use of bandwidth when streaming. It takes CD-quality music and removes the details it doesn’t think you can hear.  We appreciate the original but we struggle with the crude copy.  Essentially, lossy compression is to music what pixilation is to art.  A jpeg at 72 dots-per-inch might look okay on your phone, but not on your laptop. Ready, set, metaphor:

So, just don’t compress your audio and that fixes the problem, right?

If only.  Even with uncompressed audio, you’re still left without crucial sub-audible cues live performances convey.  Without these cues, your brain has to work much harder to process audio.  Unfortunately, lossy compression, coupled with the inaccuracies of stereophonic recordings, has detrimentally altered the listening experience in the 21st century.  The audio is hyper-accessible, but does that matter if the average music listener is only hearing a fraction of the original performance?  As illustrated above, you’re still not getting the full picture even with hi-res audioOur brains are literally, or rather musically, starving for information. So what’s the fix? How do we get what’s been lost BACK into audio? One answer is sub-audible supplementation…(continued in our next blog post)


Adapted from Dr. Roger Dumas’ TedX Talk.  Click here to view

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