less pain for language learning gain

Have any of you seen this article?
Less pain for learning gain: Research offers a strategy to increase learning with less effort

This is a pretty good research study because they had 4 different groups, which means they covered several variables to see how the results differ. The study measured the ability of the participants to distinguish between the pitches of different tones.

The Activities

There were 2 different types of activity used. The first type was to listen to a 1,000 Hertz tone and a slightly lower tone. Let's call that 'Activity A'. The second activity type was to listen to the 1,000 Hertz tone repeatedly. We'll call that 'Activity B'.