With all its peculiarities of syntax, sed leaves a bit to be desired. That’s why I was pleased to find sd, or “Search and Displace”, a tool that does what sed does but with less arcane syntax.

For example:

# prints "Corruption" (W.Barr)
echo "\"Corruption\" by W.Barr" | sd '(.+)\sby\s(.+)' '$1 ($2)'

Or just leave out the \s metacharacter in favour of a literal string:

sd '(.+) by (.+)' '$1 ($2)'

It does all the tricks you’d expect from a sed replacement. For example, named capture groups:

sed is such a useful pattern-matching and substitution tool for work on the command line. But there’s a little quirk on macOS that will trip you up. It tripped me up. On most platforms, \s is the character class for whitespace. It’s ubiquitous in regexes. But on macOS, it doesn’t work. In fact, it silently fails.

Consider this bash one-liner which looks like it should work but doesn’t:

# should print I am corrupt (W.Barr)
# instead it prints I am corrupt by W.Barr
echo "I am corrupt by W.Barr" | sed -E 's|^(.+)\sby\s(.+)|\1 (\2)|g'

What does work is the character class [:space:]:

Since I’m not fond of carrying around all my photos on a cell phone where they’re perpetually at list of loss, I peridiocally dump the image and video files to a drive on my desktop for later burning to optical disc.¹ Saving these images in archival form is a hedge against the bet that my existing backup system won’t fail someday.

I’m using Blue-Ray optical discs to archive these image and video files; and each stores 25 GB of data. So my plan was to split the iPhone image dump into 24 GB partitions. H

Generate iterated tracks at normal, 75% and 50% speeds

In previous posts I described a group of Audacity macros that create iterated tracks for chorus repetition practice. As Dr. Kjellin described we use Audacity to create a total of six repetitions per track.

Automating the generation of tracks with AppleScript

On macOS, AppleScript is the core technology used to automate routine tasks. In this case, we make extensive use of UI scripting since Audacity is not a scriptable application.

In a previous post I described macros to support certain tasks in generating source material for L2 chorus repetition practice. Today, I’ll describe two other macros that automate this practice by slowing the playback speed of the repetition.

Background

I’ve described the rationale for chorus repetition practice in previous posts. The technique I describe here is to slow the sentence playback speed to give the learner time to build speed by practicing slower repetitions. By applying the Change Tempo... effect^[Change tempo effect in the Audacity manual] in Audacity. In my own practice, I will often begin complex Russian sentences at -50% speed and progress to -25% speed before practicing the pronunciation at native-level speed. By practicing at slow speeds, it gives the learner time to appreciate how syllables are connected to each other. The prosody is more apparent.

Achieving fluid, native-quality speech in a second language is difficult task for adult learners. For several years, I’ve used Dr. Olle Kjellin’s method of “chorus repetition” for my Russian language study. In this post, I’m presenting a method for scripting Audacity to facilitate the development of audio source material to support his methodology.

Background

For detailed background on the methodology, I refer you to Kjellin’s seminal paper “Quality Practise Pronunciation with Audacity - The Best Method!” on the subject of chorus repetition practice. The first half of the paper outlines the neurophysiologic rational for the method and the second half describes the practical use of the cross-platform tool Audacity to generate source material for this practice.

This is an update to my previous post on automating iTunes on macOS to support chorus repetition practice. You can read the original post for the theory behind the idea; but in short, one way of developing prosody and quality pronunciation in a foreign language is to do mass repetitions in chorus with a recording of a native speaker.

Because in macOS 10.15, iTunes is no more, I’ve updated the script to work with the new Music app. It turns out that it’s a lot simpler. No need to dive into the application classes.