Hank Heijink is an SDE, Mobile Applications at Audible. He’s 40, handsome, lives in New York but is a native of Eindhoven, the Netherlands (also the birthplace of Philips), has a beautiful wife with a gorgeous singing voice, and is a lute player with a passion for 16th and 17th century music. Did I mention he has more degrees than you can shake a stick at, and developed The Wall Street Journal’s iPhone App?
Our multi-talented, multi-tasking Featured Geek agreed to answer all the questions we threw at him. He also sent over a couple cool links. If you like pretty sounds, you’ll click and listen when you’re done reading.
Your interest in computers began when your dad bought an Apple IIe. Do you remember when it arrived?
I must have been seven or eight. I remember being allowed to stay up late, watching my dad put the computer together and playing a game that came on the diskette that was supposed to introduce us to the Apple. I remember it featured a rabbit and carrots, and that it was funny, at least to a young boy. My father still has the computer somewhere in his attic, I think.
Tell me about your Ph.D. You studied a combination of music, psychology and computers.
I studied redundancy control in music performance and in the analysis of music performance. Redundancy control is also referred to as the “degrees of freedom” problem in motor control, which means there are many ways to perform a task, even something simple like picking up a cup. Such a move involves coordinating several muscle groups at the same time, and it’s surprisingly difficult to model. Then again, given how long it takes a baby to learn to coordinate movements, maybe it’s not that surprising after all. I looked at how expert guitar players position their fingers within the frets, and how they change the placement of those fingers in anticipation of a something difficult coming up.
I was never much focused on research there, but helped with experiments, and their analysis. The focus of the research was, again, how people plan reaching movements. It turns out to be even more complicated than most people think, involving two separate processes and coordinate systems for the reaching part and for the final adjustment of the movement. I co-wrote an article on the subject in the Journal of Neurophysiology
This is where I learned programming in Objective-C. The lab was completely Mac-based. In fact, when I arrived, the experiments were run by a Hypercard stack, and this was in 2006.
Do you find any commonalities between playing music and programming ?
They’re not that similar on a practical level, but on a theoretical level they are both about communication. Communication in programming is about as stylized as it gets and I can appreciate the beauty of the syntax of programming languages, as well as the beauty of the solution to a problem.
Performance is a much more direct and subtle form of communication, with other musicians and with the audience. I find the two complement each other more than they are similar. It helps me in both areas too. I think I’m a better programmer because I play music, although I’m not sure if I’m a better musician because I’m a programmer.
I’m a big fan of Terry Pratchett. It’s not the deepest of literature but it’s extremely enjoyable. I tend to gravitate toward science fiction, although I think the term doesn’t mean that much anymore. I’m currently reading Death’s Master by Tanith Lee. I’m also reading Beautiful Code, which is a very inspiring book.
Tell us about The Wall Street Journal App.
I had lots of Mac experience by then, and done some iPhone work. I started looking at it as soon as iOS 2.0 came out, and wrote a little tuner application for my lutes (iPegs, it’s still in the App Store). I basically wrote the app from scratch and architecting it alone was an interesting challenge. The biggest problems I found were with syncing customer favorites with the cloud. On a mobile device connections are notoriously unreliable, so there are many different edge cases you have to think through and address. However, this is also the charm of working on mobile: It’s almost sleight of hand. You have to give the user the illusion that the device is more often online than it actually is, and that your application is faster.
What do you doing right now for Audible?
I’m the lead developer for Audible’s iOS application, and you’ll be seeing some very cool new features in the near future. Audible and Amazon just launched Whispersync for Voice and Immersion Reading. Whispersync for Voice enables you to keep your place while switching back and forth between reading a Kindle book and listening to the corresponding Audible audiobook, while Immersion Reading allows you to listen to an audiobook and read at the same time. We’re very excited about both innovations.
Audiobooks are a very interesting domain because there’s a lot of data involved (audio files tend to be over eight hours long and in the range of 200 MB and up) and the whole ecosystem is very complicated, even more so now that you can switch between ebooks and audiobooks. There’s a lot of very sophisticated technology, to mention a lot of very clever people, behind it and we have the people and the drive to aim even higher.
- Different Learned Coordinate Frames for Planning Trajectories and Final Positions in Reaching [Journal of Neurophysiology]