The Machine Learning delusion

This morning my personal biological computer detected a correlation between these two articles:

Sony’s SenseMe™ – A Superior Smart Shuffle

Machine learning: why we mustn’t be slaves to the algorithm

In the first article, the author is praising a “smart shuffle” algorithm that sequences tracks in your music collection with various themes such as “energetic, relax, upbeat”. It does this by analysing the music’s mood and tempo. It sounds amazing:

“I would never think of playing Steve Earl’s “Loretta” right after listening to the Boulder Philharmonic’s performance of “Olvidala,” or Ry Cooder’s “Crazy About an Automobile” followed by Doc and Merle Watson playing “Take Me Out to the Ballgame,” but I enjoyed not only the selections themselves but the way SensMe™ juxtaposes one after another, like a DJ who knows your collection better than you do…what will “he” play next? Surprise! It’s all good.”

And the algorithm’s effects go beyond mere music:

“SenseMe™ has brought domestic harmony – interesting selections for me and music with a similar mood for her. That’s better than marriage counseling! “

The author of the second article takes a more sceptical view. He notes the dumbness of Machine LearningTM algorithms, but says that

“…because these outputs are computer-generated, they are currently regarded with awe and amazement by bemused citizens …”

He quotes someone who is aware of the limitations:

“Machine learning is like a deep-fat fryer. If you’ve never deep-fried something before, you think to yourself: ‘This is amazing! I bet this would work on anything!’ And it kind of does. In our case, the deep fryer is a toolbox of statistical techniques. The names keep changing – it used to be unsupervised learning, now it’s called big data or deep learning or AI. Next year it will be called something else. But the core ideas don’t change. You train a computer on lots of data, and it learns to recognise structure.”

“But,” continues Cegłowski, “the fact that the same generic approach works across a wide range of domains should make you suspicious about how much insight it’s adding.”

I have been there. Machine learning is one of the most seductive branches of computer science, and in my experience is a very “easy sell” to people – I use it in my job in actual engineering applications where it can be eerily effective.

But if algorithms are so clever and know us so well, why are we using them only to shuffle the order of music? Why not cut out the middleman and get the computer to compose the music for us directly? The answer is obvious: it doesn’t work because we don’t know how the human brain works, and it is not predictable. By extension, the algorithms that purport to help us in matters of taste don’t actually work either. As the Guardian article says, all we are responding to is the novelty of the idea.

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Pop and click remover, old electronics magazines

Just saw a short article about a new product that aims to remove the pops and clicks from vinyl records. It…

…digitizes the signal at 192/24 bit resolution and then uses a “non-destructive” real time program that removes pops and clicks without, the company claims, damaging the music.

…In addition to real-time, non-destructive click & pop Removal the SC-1 features user controllable click & pop removal “strength”, a pushbutton audiophile-grade “bypass” that lets you hear non-digitized versus digitized signal (for when you don’t need pop and click removal), iOS and Android mobile app control and 192/24 bit hi-res digital processing.

Of course it is highly ironic that a vinyl enthusiast should need the services of the digital world to improve the sound of his recordings. And it is obvious (surely) that the digital stream could be stored for later replay without needing to further degrade the original vinyl or wear out the multi-thousand dollar stylus that is no doubt being used. (Omitting to mention the most obvious idea of just listening to a digital recording…)

The aim of the product reminded me of a certain project in an old electronics magazine, a huge number of which I still have in a set of bookshelves that I haven’t touched since 1990 – the date of the last magazine I seem to have bought. Sifting through them, it is amazing how familiar the front covers still are –  a measure of the intensity of youthful hobbies.

click-eliminator-2

From Electronics Today International in April 1979, the project I remembered was a ‘Click Eliminator’ for vinyl records based on an analogue CCD delay line. The idea was to insert a few milliseconds of silence in place of the offensive click. Here’s how it worked:

click-eliminator1

Electronics Today International was the magazine I would go to WH Smiths for on a Saturday, being terribly disappointed if the latest issue wasn’t in. I would say more than 50% of issues featured an audio or hi-fi project: from 1982 an active speaker project for example, or from 1986 “Can Valves make a comeback?” with an accompanying valve amp project. There were any number of MOSFET amps, phono pre-amps, tape noise reduction units. Electronic music featured prominently with projects for effects pedals and synthesisers galore. I devoured this stuff.

Other magazines included: Practical Electronics, Wireless World, Everyday Electronics, Elektor, Electronics and Music Maker, and one I didn’t recall Hobby Electronics. I also bought any number of computer magazines. I have never thrown any away, so I have hundreds of them gathering dust.

Kii Three Review

Just saw this review of the Kii Threes by mastering engineer Bob Macc. He seems rather pleased with them:

…everything is just tight, accurate, and not smeared in time or pressed-sounding. Kick drums on these speakers are ridiculous in their tightness and accuracy. Acoustic and electric basses are the very definition of the word ‘articulate’. The time-coherency extends, of course, across the whole spectrum. Transients are, well, transients.

The imaging on these speakers is also absolutely unbelievable, in all dimensions. The front to back depth is unreal; room information is conveyed incredibly well. You’re there. In fact it might be the depth that astounded me more than anything else. The stereo image is absolutely enormous, involving, and everything sounds real. Drums pop out like drums do (or don’t, if they don’t). The main acoustic guitar in Holland and Habichuela’s ‘Hands’ was unbelievably real. The sound is huge, and absolutely pristine in all regards.

They are incredibly revealing – I heard things in tracks I know extremely well that I have never heard before. I heard micro-movement inside tracks from compression/sidechaining that I’ve never heard before. I heard mistakes in work by very famous engineers in tracks I’ve listened to a million times. I heard mistakes in my own work (tiny ones, I promise!) that I absolutely would not have allowed to pass had I heard them previously. That kind of says it all.

The whole time though, you’re thinking; ‘how do those tiny little speakers make all that sound?!’. With eyes closed and a good-sounding track playing, the room is absolutely full of sound. When you open your eyes, it’s almost as if the illusion is destroyed – there’s simply no way those little things can produce all that sound. But they do, and they do it easily and effortlessly.

I really am going to have to get in touch with the chap at Purité Audio (who posted this review on HiFi Wigwam) and see if he’ll let me have a listen…