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.

Technique

You can see that we’ve just add a single additional step (02) to the previous iteration generator macro - in this case, reducing the tempo by 50%.

If you want to reduce the speed by only 25%, then you just need to alter the corresponding command 02:

Download the files [Kjellin sentences 50.txt](/attachments/2020/07/16/Kjellin\ sentences\ 50.txt) and [Kjellin sentences 25.txt](/attachments/2020/07/16/Kjellin\ sentences\ 25.txt) and on macOS install them at ~/Library/Application Support/Audacity/Macros.

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.

Rationale for this project

Preparing source material (sentences of about 2 seconds duration) for this method is not difficult, but the steps are repetitive. Fortunately Audacity offers the ability to script its behaviour through macros (Tools → Macros...). Two macros are described here. Neither are complex, but they do chain common commands in Audacity, making it faster to produce material for chorus repetition. The first macro just trims silence from the clip and compresses its dynamic range. The second takes a clip, ideally a single sentence, adds 0.65 seconds of silence at the end, then replicates the clip + the silence 5 times for a total of 6 repetitions.

Macros

Truncate and compress

To install this macro, download the file (Download ZIP.) On macOS, you can move the file to ~/Application Support/audacity/Macros. I’m not sure where it goes on other platforms; check the manual.

To use the macro, start with the sentence clip you want to process and invoke Tools → Apply Macro → TruncateAndCompress.

You can play around with different parameters if you need to trim more or less silence or if you want to change the compressor settings.

Kjellin Sentences

This macro will take a prepared clip, ideally a single sentence and create six total iterations with 650 ms of silence between each iteration.

To install the macro, download it from the following location using Download ZIP, decompress and place in the Macros directory as above.

You will need one additional step before this is usable. You will need to create a user preset for the Generate silence tool. Navigate to Generate → Silence... and create a preset named “650ms” so that the macro can use it.

Again, to use it, just prepare a track with a single sentence you wish to use and then Tools → Apply Macro → KjellinSentences.

Enjoy and keep practicing!