Last month I introduced an octave inversion algorithm that can take any sound recording and flip its octave upside down. I’d now like to review a few more audio processing tricks I’ve been experimenting with lately: melodization, split-band cross-modulation, time blur, frequency blur, and window-reversal. I’m not sure each of these techniques is entirely original,…
You probably know what it’s like to hear a recording played backwards. But have you ever heard one that’s had its octave flipped upside down? The idea recently came to me of modifying a 1930s voice scrambling technique for this purpose, and the results have been extremely cool—even addictive. As far as I’m aware, this…
What would you say if I were to offer you a digital image from the 1740s? Not an image from back then that just happens to have been digitized, mind you, but an image that was then already digital. If you’re one of those people who think “digital” means “the convergence of social media, mobile…
The oldest recorded human voice that can be heard intelligibly today dates from April 9, 1860: a ghostly snippet of the folksong “Au Clair de la Lune,” played back in March 2008 after lying silent for nearly a century and a half. For twenty seconds, someone living in the Second French Empire of Napoleon III…
The latest round of additions to the National Recording Registry for 2016 has recently been announced, and if you’d like to celebrate the occasion with a toast or two, some of the newly inducted recordings might just be able to guide you through the process. I’m thinking here of the first item on the list,…
Motion pictures of specific historical eclipses exist dating back more than 375 years. In this post, I’ll present some of the oldest surviving examples for viewing in motion for the first time (as far as I’m aware): eleven from the seventeenth century, four from the eighteenth century, and six from the nineteenth century. That makes…
Some kinds of audio restoration are on pretty firm ground these days: declicking and decrackling, for instance, or noise reduction. But speed variance correction—the removal of wow and flutter—remains an extraordinarily daunting challenge. It has a reputation for being the high-hanging fruit on the audio restoration tree, akin to rocket science or brain surgery. The…
