Difficulty of Korean Phoneme Production and Perception for L2 Learners

It's a new year, and a (renewed) resolution not to let this blog fall completely by the wayside... so, time to start sharing little slices of my dissertation research!

Very briefly, my dissertation is a language assessment project related to the pronunciation of L2 Korean phonemes. I developed a diagnostic test that provides information on how well learners can produce and perceive Korean phonemes. I collected test data from 198 adult learners from a range of first language backgrounds and overall proficiency levels.

After converting each phoneme score to percentages and averaging across learners, here's what I found for the accuracy of production (y axis) and perception (x axis) (graphs made in R with ggplot2):

For those of you who don't read Korean, but do read the International Phonetic Alphabet, here's another version of the chart:

In many ways, these results aren't so surprising. For example, the tensed consonants of Korean were the most difficult to produce. And in general, there's a fairly strong (moderate) correlation between production and perception accuracy (of course, this is averaged across learners, so should be taken with a grain of salt).

But there are some interesting things going on. For one, learners actually did reasonably well with perceiving some of the tensed sounds, like /d*/ (about 80% accurate). There were also some cases in which production accuracy exceeded perception accuracy; this is something that goes against some stronger versions of L2 speech learning theory, but I'd chalk much of it up to differences in task difficulty. Because the production items were scored according to criteria in line with John Levis' (2005) Intelligibility Principle, productions that were confidently identifiable were scored as correct, even if they weren't exactly within native-like ranges in terms of temporal/acoustic qualities. Reception items, however, were simply right or wrong based on a choice, and these items utilized native-speaker recording of standard Korean phonological contrasts. 

Reference:

Levis, J. (2005). Changing contexts and shifting paradigms in pronunciation teaching. TESOL Quarterly, 39, 39-377. https://doi.org/10.2307/3588485