Monday, January 14, 2019

How To Listen Critically

Critical listening is an important skill for sound engineers & artists of all kinds. In this compendium of tips, I focus on critical listening for more "analytical" purposes, rather than more "creative" purposes. I present ideas for critical listening that may be useful in contexts such as:
  • Mixing a song
  • Mastering an album
  • Fixing problems in recorded material
  • Identifying issues in a musical system like a live rig or a modular synthesizer patch
Critical listening is also required in a variety of creative contexts, such as critiquing the musicality of recorded performances. Hopefully, some of these tips are useful in those contexts, too. But my main focus is on ways to hear technical problems.


Before you try to listen critically, it's most helpful if you:
  • Know your listening system.
  • Have a quiet background. Don't try to listen critically while you ride a train.
  • Have a "good enough" listening system. For example, it's hard to hear problems in the bass if you are listening on phone's built-in speaker.
  • Make time and space for critical listening.


The most important tools for critical listening are your ears and your brain. Here are some additions that may be useful:
  • A variety of listening systems: Conventional wisdom in music production is to check how well a mix "translates" between listening systems. Possible alternative listening systems include:
    • Near field monitors
    • Ear buds
    • High quality headphones
    • A Bluetooth speaker
    • Car stereo
    • iPhone speaker
    • Laptop speaker
    Note that headphone-based systems are substantially different to speaker-based systems, especially for spatial imaging. Room characteristic and treatments play a big role, too.
  • Trusted reference tracks: Everyone has their favorites. The main thing is that you know the music and the sound very well on a range of systems, and that you admire the production. Try out others' suggestions here and see what you like. For about ten years, my reference tracks have been "Rods and Cones" by Blue Man Group and "Right in Two" by tool.
  • Analytical music software tools: Match EQ in Logic Pro is good for taking EQ differences out of the equation, both to help you focus on other aspects and to fix problems. Spectrum analyzers can be helpful sometimes. The spectrogram view in Audacity also has its uses. Python + numpy + matplotlib (or MATLAB) is the most flexible (and difficult) approach. This opens the big, related topic of visualization and analytical qualification.


Critical listening is listening plus critical thinking. Everything that you know about critical thinking ought to be applied to your critical listening. Here are some tips based on my reading and experience:
  • Focus: What problems are you listening for?
  • Anti-focus: What problems may exist that you are not listening for? Try to see the forest for the trees.
  • Repetition and fatigue: Some problems elude the first hearing or require many subtle comparisons. This gets boring and tiring -- sometimes fast! One strategy is to listen over and over, form an opinion (take notes!) then stop for a long break. After the break, listen again and see if you feel differently. The long break might be an hour, or until the next morning, or it could be 6 months. 
  • Contrasts and background: We hear differences and rapidly become acclimatized to similarities. Often it's easy to determine which of two options is better with a systematic, direct AB test. Also, you can try to reset your background expectations by listening to alternative sounds. This could be your favorite reference tracks played back on the same system or it could be a familiar quiet acoustic scene like the hum of your fridge (and nothing else) while you have a coffee. Another option is the sound of city traffic when you go for a walk. My ideal break from critical listening would be a walk through a quiet forest with a small stream and birdsong.
  • Sleep makes for a good break. Sleep is typically an extended period of silence or quiet. The "morning person" vs. "night person" dimension of your personality may or may not correspond to the best time for you to listen critically. Sleep also helps reset critical thinking -- which emphasizes the importance of taking detailed and specific notes -- tomorrow morning you may hear and think an entirely different thing! Critical listening is, therefore, hard to rush.
  • Level makes a big difference. Keep in mind that people tend to like the louder of two options. Louder also fatigues you faster. (Brighter is like louder.) Our ears' frequency sensitivity depends highly on level: we hear more bass at loud volumes (refer to the Fletcher-Munsen equal loudness curves). One approach is to use Bob Katz's K12 metering system. [Note to self: Look this up and, if possible, try it out.] You can get SPL phone apps, e.g. NIOSH SLM. Level calibration is harder on headphones. 
  • "Hearing around corners:" This is less analytical critical listening and more of a creative act. Sometimes you hear different and surprising aspects of a sound in different contexts. Different and limited listening systems is one approach here, also:
    • Listen in the bath (water running or not).
    • Listen while falling asleep or meditating.
    • Listen while kids are yelling.
    • Listen while simultaneously playing back The Beatles.
    • Listen very quietly. (Sometimes you can even hallucinate interesting things in this way!)
    • Listen to tracks soloed. If it's not your song, then try to get the stems. 
    • Reverse it and listen to that. 
    • Slow it down 2x and listen to that. 
    Many other ideas are possible here; this is an interesting topic in its own right.
  • Know yourself and your own limitations -- but also aim to grow in ways that matter to you. People aren't born with "golden ears;" they learn to be good critical listeners. Having "golden ears" isn't some kind of either-or thing; we are all on a journey and we all can have well-reasoned and informed opinions. We all ought to draw on each other's experience and expertise. If you know someone whose taste and judgement you highly respect, then try to learn from them. Listen to material together and try to hear the subtleties that they hear.
  • Check the solution: You had a song, you listened critically, you found a problem, now you think have fixed it. You need to listen critically again, and even compare before and after. Blind testing is useful here, like an ABX test. There are plug-ins to help with this. Also, you can get a second opinion from someone whose judgement you trust. The industrial-strength solution here is to do a statistical study in controlled conditions with numerous (like >30) listeners. However, running listening studies is an art unto itself, for example, do you use expert golden-eared listeners, or naïve members of the public?
  • Know when the solution is good enough. Perfect is the enemy of good, but so is mediocre. Have high standards, and keep the alternative in mind. For example, if you can't fix this problem in a mix, then do you simply not release the song? Maybe it's better to release the song if it's strong musically -- or maybe you can afford to re-record the problem section.


I presented a variety of tips and strategies to help with the art of critical listening for analytical purposes. Critical listening is an art and a skill. Critical listening is grounded in critical thinking. Having good equipment helps, but experience, skill and tenacity are more important.

Post script

Keep your ears in good health. For me, this means that I need to regularly ensure that my ears aren't filling up with wax.

Tuesday, December 4, 2018

Dress for failure

Serious aversion to big failures demands a strange sort of attraction to small failures. As a firefighter ought to love fire a little, so the engineer ought to love failure a little. Antifragility at the system level requires the fragile components to die so that they can be reborn stronger. Let the bolts break, so the bridge may survive. Let the service crash, so that the operating system can stay running.

Lack of exposure to failure in school will cause our children to be both over- and under-confident. Resilience to failure is enormously valuable. We ought to fail kids more often (without emotional punishment), so that they get used to it. In both formal education and in the ongoing learning of people on the workforce, we need to simultaneously reduce the consequences of failure and increase our exposure to failure. In science, engineering and software development (at least), let’s get good at failing. 

The value of failure is in the insight gained while one is getting back up again. We have a social stigma attached to failure and we are preoccupied with the outcome while we discount the importance of the process. The antidote is to study and celebrate failure. 

Let’s fail more often. 
Let’s fail better. 
Fail great. 
Fail marvelously.

Sunday, October 21, 2018

New music & art: "Electrons and Void"

Today I released a new album of music! Get Electrons and Void on Bandcamp here.

The (long) development of this album spanned a period of disruptive internal change in my life, which is ultimately reflected in the album itself. Mostly in the accompanying words, to a lesser extent in the music itself and probably least of all in the photographs that I included here. The change was something akin to what happened to Saul, simultaneously on the road to Damascus, on the way to becoming the Apostle Paul, and to becoming (temporarily) blind. But for me, the change was sort of the opposite of what it was for Paul: anti-metanoia, perhaps. Under a given condition, x, I passed into a new state, and under another condition, y, I passed into another state, and these two states may have been potential in my earlier self, but only in the sense that they came to be developed under the conditions, x and y. But it is plain that I did not escape the difficulties concerning metaphysical predication in this changing world; indeed, such difficulties included intense personal pain, even mental illness. Not at all to say that this transition and the subsequent pain are somehow decodable from the sounds of my instrumental music, but the echo and reverberation of my changing self is inevitably there, in however ghostly a form. 

Conversations with the Abyss
First was there Mind the Generative Law of All;

Second to the Firstborn was Liquid Chaos;

Third Soul through toil received the Law.

Wherefore, with a deer's form surrounding her,

She labours at her task beneath Death's rule.

Now, holding sway, she sees the Light;

And now, cast into piteous plight, she weeps;

Now she weeps, and now rejoices;

Now she weeps, and now is judged;

Now is judged, and now she dieth;

Now is born, with no way out for her; in misery

She enters in her wandering the labyrinth of ills.

Acute, Angular

The hardest part of working with wizards is undoubtedly the project management aspect. Very few large, wizard-heavy projects are completed on time. Not only because wizard are infamously lazy, but also because magic is so poorly understood that a monkey can manage wizards at least as well as the so-called professionals.

Medium Machinebuilding

Promethean, we dared
A weighty energy
An instant
Pandora so radiant
That prisoner’s
Mad temptation
Defect now
Then Electrons
And Void
Прометею-подобные, мы осмелились
Тяжелая энергия
Как Пандора лучистая
Радио вспышка
Того заключенного
Сумасшедший соблазн
Дефект сейчас
Потом Электроны
И Пустота


Comment ca va?
Je suis mort.

"One result of the dissolution of the persona is the release of fantasy... disorientation."


Warning! This song contains beats Known by the State of California to Cause Harm, including but not limited to reproductive harm, musculoskeletal harm, cardiovascular harm, gastrointestinal harm, pulmonary arterial harm, hypertension, dyslexia, paranoia, diarrhea, schizophrenia, metanoia, transcendent hyper awareness, dissociative ocular inflammation, transcranial mental fatigue, sleepiness, depression, general anxiety syndrome, fits of uncontrollable laughter, complex anxiety syndrome, itchy rashes, irritability, and sudden death.
Discuss this song with your doctor if you or someone in your family has a history of kidney disease or allergic reactions to overwhelming rhythms.
This song may be monitored or recorded for quality assurances purposes.

Use only as directed.

This notice void where prohibited by law.

Known by the State of California
to Cause Harm

This agreement (“legalwash”) is binding in a billion different jurisdictions and takes effect immediately even if you don't know about it at all. This agreement only seems to be written in English; because this agreement is written in legalspeak, it means whatever we want it to mean.

These are the standard terms and conditions, written to maximally disadvantage you. We follow industry best practices in order to maximize our potential for abusing you. The government even legislates that we're allowed to come into your house and eat all the food in your fridge, whenever we want to.

You agree not to hold us liable for all the evil deeds that we plan to deliberately perpetrate. Oh man, we're gonna do some nasty stuff to you and it's gonna be so fun. Actually, we'll start by throwing your toothbrush on the bathroom floor.

All disputes are to be resolved by arbitration, and all disputes will be resolved in our favor. Don’t even bother trying to sue us, we have a dope team of lawyers. Besides, by accepting these conditions, you agree to always agree with us on all matters.

Click here to acknowledge that you, either in a fit of madness, or as a barefaced lie, have read and accepted these terms and conditions. Click here fool, I dare you.

Stygian Confabulation

“Sadly,” Death said, “I will betray you, and love you no more.”

But everything is one thing only.

Tudo é uma coisa só.

The Great, Dead Expanse

I am made of ash
The slightest gust of wind
Will shatter me
Into a million atoms
Unique in my deconstruction
Fated for a sudden undoing
A return to nothingness
To pure abstraction

That Shadow

“For it is written in the prophet, ‘But a ghost, a demon, leaves no print on the ground.’”

From the past, reaching past now and into the not yet. The mirror reverberates, a thing and that same thing again. A sight and a feeling, heard as if already known.


What do you do when your life full of joy and hope
dissolves into angles of anxiety and lines of grief
when the cold walls of this void world close
and the gray sky weeps the loss of every fragile moment
that you once held dear?
The answer comes echodown at a distance
that the hour will come
when the complexity of life gives way
to the brutal simplicity of death
fears quieted and worries stilled
in pale abandonment and shrill remorse
the abrupt finite nature of all things
stands still before us
whispering, whispering
over and over and over and over and over…

--- ...- . .-. / .- -. -.. / --- ...- . .-.

Analogue Superstitions

They came to rob my peace
But I don't have any peace
She said that in a storm
The water deep in the ocean is quiet and still
And that the emotions of the righteous can be like that ocean
Deep peace.
But they found that I'm not like an ocean
That I have no deep peace
Only turbulence


Knowing where you want to go but not knowing how to get there.
Or knowing where you are but not knowing where you mean to go.
Standing at the crossroads, unsure which way to go.

Other times, standing in the middle of a vast, featureless desert, the terrible void.

When that well of reasons dries white as a bone, lost means not knowing why.


Music, words & photography by ilam stone / Peter Raffensperger
Cover art by Industrial Grace Restoration / Rebecca Hill

Conversations with the Abyss: Text from the Naassene Fragment, translation from Mead, G.R.S (1906). "The Myth of Man in the Mysteries". Thrice Greatest Hermes: Studies in Hellenistic Theosophy and Gnosis. I. London and Benares: The Theosophical Publishing Society (Public Domain)

That Shadow: Quotation from Epistula Apostolorum 11, translation by Hennecke and Schneemelcher, New Testament Apocrypha, 197 (Fair use as per Westminster John Knox Press guidelines)

Medium Machinebuilding: photo by Lauren Raffensperger. Russian translation by Anastasia Shchepetkina.

Empty: Quotation from Jung, Two Essays; page 277. (Fair use as per Princeton Press guidelines)

Wednesday, June 21, 2017

Every once in a while, imagine starting over

Here’s a suggestion for when you’re working on a long, complicated project. Every once in a while, work through the thought experiment of starting your project over. Re-examine every aspect on a fundamental level, relating the complicated abstractions and mental shortcuts to your basic guiding principles. Given everything you learned in the course of the project so far, would you do it the same way again if you started from the very beginning?

This thought experiment could have many different outcomes. When you started the project, you guessed at the right direction, but the benefit of hindsight may suggest a better way. Parts of the project may be kept around only because of the sunk cost fallacy. Maybe you’ve learned more about what the requirements really are. Maybe it’s time to kill this project and start a new one. Maybe the project is too long or too complicated and should be broken down into several smaller projects. Maybe your plans for the rest of the project need to change. Or maybe you can have more complete confidence in your current approach. Most likely you will find at least a few small things to tweak.

Let me give you a hypothetical example. Suppose that you have a software system with two threads: one that produces data objects and one that consumes them. You do extensive performance profiling and find that both threads run too slowly, so you spend some time speeding up both threads. Eventually, you speed up the consumer thread until it only takes 12 CPU instructions per incoming data object. If you were under time pressure to deliver a critical patch, then you’d be happy with your optimizations and you would ship what you had. But if you thought through what you would do if you were to start over, then you would probably decide that using a consumer-producer multithreading architecture is the wrong strategy entirely because a single thread is good enough.

Around the start of 2013, when I was working on my PhD, I was wandering in circles around a particular problem: I wanted to discover the conditions required for a pair of Q-learning agents to learn to take turns in a simulated context. I parameterized the agents’ reward functions and tried to discover a pattern that would compactly describe how to incentivize turn taking. I went down a few blind alleys: genetic algorithms, linear decompositions and staring blankly at a simple visualization of the problem. Eventually, I realized that game theory is the correct approach for analyzing this kind of multi-agent scenario. At that point, I revised the entire plan for my PhD so that the next part was focused almost entirely on game theory.

Most of your time must go to detail work, so when is it time to step back and look at the big picture? Unfortunately, you probably won’t reach an epiphany moment where you know its time to rethink the project, like I did with my PhD. No tree will scream “this is the wrong part of the forest.” At the start of this essay, I suggested that you imagine starting over "every once in a while,” but a definite schedule may be helpful. How about 1 January each year? Or the first day of each month? What projects are you working on now? Do you have one where you’ve focused exclusively on details for a long time? Maybe now is the time to imagine starting that project over

Wednesday, April 26, 2017

The Anti-Jefferson Bible

"The Life and Morals of Jesus of Nazareth" by Thomas Jefferson, also known as the "Jefferson Bible," is a cut-and-paste work derived from the New Testament gospels, where the life and teaching of Jesus is (sort of) preserved but the miracles are taken out. In this essay, I consider how the Jefferson Bible could be compressed using the canonical gospels as a codebook, and I present a new sacrilegious work, jointly derived from the canonical gospels and the Jefferson one: The Anti-Jefferson Bible, a satirical book with all the gospel verses that Jefferson excluded and only those verses.
Painting of Thomas Jefferson by Rembrandt Peale
I first encountered the Jefferson Bible when my grandpa sent me a print copy of the book, along with a few other pseudo-Christian humanist titles. I found the Jefferson Bible rather boring, because my familiarity with the canonical gospels caused the book to have a low per-page entropy. That is, I already knew the story; the only interesting part was seeing what Jefferson chose to leave out. But just how much information is there in the Jefferson Bible?

The Jefferson Bible is a redaction of the King James Bible, taking verses exclusively from the four gospels: Matthew, Mark, Luke and John. These books are in the public domain and you can download them from Wikisource:
When I transmit a message, I can compress that message more if the recipient of my message already shares some information with me. For example, if I know that my grandpa has a copy of WinZip, then I could sent him a file that uses the zip compression format, which uses fewer bits. Frequently, when we encode something, we just assume that the other end knows the format because we chose ubiquitous file formats: we have pre-shared knowledge of the encoding. I will estimate an upper bound on how much information Jefferson contributed to the world based on the information required to encode the Jefferson Bible, given the King James Bible as pre-shared knowledge. Copies of the King James Bible are much more common than copies of the Jefferson Bible, which half-justifies this approach.

Matthew, Mark, Luke and John comprise 3778 verses in the King James Bible. For each verse that Jefferson copied in whole, I will consider that he has added a full 12 bits of information: enough to choose a verse in the canonical gospels. The Jefferson Bible includes some verses only in part; I will encode those verses as straight ASCII, at 7 bits per character. The Jefferson Bible has 1028 verses: 450 from Matthew, 94 from Mark, 338 from Luke and 146 from John. Actually, some verses in the Bible are exact copies of other verses, so alternative counts are possible.1 Thirty-eight verses are partial matches. With this encoding the Jefferson Bible requires 29520 bits or 3.6 kilobytes. If we encode all 116037 characters with ASCII, then we require 812259 bits or 99 kilobytes. My scheme achieves a 3.6% compression ratio. All this is to say: Thomas Jefferson did not add much information to the corpus of human knowledge in his humanistic redaction!

The figure below graphs the relationship between verses in the Jefferson Bible and where those verses are found in the canonical Gospels. Observe that much of the graph gently slopes upward: most verses in the Jefferson Bible are followed by their successor in the canonical Gospel. I could have compressed the Jefferson Bible even further if I choose a more clever encoding scheme that made use of this knowledge!

Wikipedia tells us that "Jefferson's condensed composition is especially notable for its exclusion of all miracles by Jesus and most mentions of the supernatural, including sections of the four gospels that contain the Resurrection and most other miracles, and passages that portray Jesus as divine.” In an attempt to quantify Jefferson’s tendencies, I computed the relative frequencies of each word that appears, both in the canonical gospels and in the Jefferson Bible. Some words are much more likely to occur in the Jefferson Bible, than in the canonical gospels, while others are much less likely in the Jefferson Bible. Below is a table listing 140 words:
  • the 60 words that have the greatest increase in frequency in Jefferson Bible (relative to the canonical Gospels),
  • 20 words that occur with almost equal frequency
  • and the 60 words that have the greatest decrease in frequency in the Jefferson Bible (relative to the canonical Gospels).

More likely in Jeffferson Bible Almost equal More likely in canonical gospels

We see that ‘believed,’ ‘fulfilled,’ and ‘healed’ are more likely in the canonical Gospels, while all the words that are more likely in the Jefferson Bible are plain and devoid of spirituality-related meaning, like ‘one,’ ’thy,’ and ‘give.’ Interestingly, ‘prophet’ is more likely in the canonical gospels, but ‘prophesy’ occurs with roughly equal frequency in both.

We have a window to Jefferson's heart in what he left out. Presumably, he could have written a short essay describing how the gospels are useful for learning morals but that the miracles can’t be trusted. Instead we have the Jefferson Bible, which, in some sense, is a polemic against the supernatural in Christianity that pretends to replace the gospels. Regardless of whether or not Jefferson is right to reject the supernatural on a factual level, his approach is ridiculous. To satirize the Jefferson Bible, I produced the “Anti-Jefferson Bible”, which includes all the verses in the canonical gospels that are not present in the Jefferson Bible. Where the Jefferson Bible included part of a verse, then the Anti-Jefferson Bible includes the remainder, even when that remainder is not a complete sentence.

From a technical literary perspective, the Jefferson Bible is a gospel harmony. An early gospel harmony was Tatian’s Diatessaron; modern attempts include various Bibles that are reordered ‘chronologically.’ Jefferson’s work is most akin in form to the heretic Marcion, who introduced his own canon list which included a version of Luke’s gospel that was edited to fit his gnostic theology. There are no new heresies! The Anti-Jefferson Bible is not a thoughtful gospel harmony, and given copies of the Jefferson Bible and the King James Bible, the entropy of the Anti-Jefferson Bible is tiny indeed. I make no claim that the Anti-Jefferson Bible has novel information. My work’s highest possible hope is to highlight the absurdity of Jefferson’s redaction.


1. Because the gospels have redundancy, we can compress them, too. Matthew and Luke seem to draw heavily from Mark, as well as from a hypothesized source, Q. I’m curious as to the entropy of the gospels themselves, which would be a useful point of reference here.