Evaluating non-native perception tasks
Ryan Lidster, Franzi Kruger, and I are working on a number of studies in which we examine the relationship between various non-native perception tasks: free classification, perceptual assimilation, AXB, and oddity (and likely similarity judgment in the future). Our next steps are to test the perception of Finnish vowels and Finnish length by Japanese and American English listeners and the perception of Arabic consonants by American English listeners. Here are some highlights from our findings so far on the perception of German vowels by American English listeners:
L2 lexical representations: Alternate or fuzzy?
In previous research (Daidone & Darcy, 2014; Darcy, Daidone, & Kojima, 2013) we've found that learners have difficulty rejecting incorrect pronunciations of words with new phonemes, regardless of whether they can accurately perceive these new sounds. For example, English-speaking learners of German often will accept a non-word with a back vowel as a real word when the real word actually contains a front-rounded vowel, e.g. they will accept [konɪç] as a word when the word is actually könig [kønɪç] 'king.' However, from this research it was unclear if learners' lexical representations were fuzzy or alternate. By fuzzy, we assume that a difficult novel phoneme is underspecified such that the learner would accept many different possible realizations of a word, e.g. könig as [kønɪç], [konɪç], [kunɪç], or even [kenɪç]? If a learner has alternate lexical representations, then we hypothesize that they would only have a limited number of possible realizations that they will accept, e.g. könig only as [kønɪç] or [konɪç]. The current project with Isabelle Darcy, Franzi Kruger, and Ryan Lidster tries to determine which of these two possibilities is true for learners' lexical representations of words containing front-rounded vowels in German.
The effects of input, native-language phonology, and individual differences on lexical representations
Previous research on the lexical encoding of novel L2 contrasts has shown that accurate perception is likely necessary but not sufficient for accurate lexical representations. Even when learners are able to perceptually distinguish L2 sounds, they often struggle with encoding these sounds contrastively in lexical representations, and perception ability has been found to account for only some of the variance in lexical encoding accuracy. In my dissertation I plan to investigate the ability of learners to encode novel words containing the Spanish tap and trill, a contrast that has been shown to be easily discriminable for English-speaking learners and even naïve English listeners, yet difficult for learners to encode accurately in lexical representations. By investigating an easily perceptible contrast, this study will focus on other factors that may explain lexical encoding difficulty beyond perception – unreliable L2 input, the L1 phonological grammar, and learners’ individual differences in cognitive abilities and vocabulary size.
Ryan Lidster, Franzi Kruger, and I are working on a number of studies in which we examine the relationship between various non-native perception tasks: free classification, perceptual assimilation, AXB, and oddity (and likely similarity judgment in the future). Our next steps are to test the perception of Finnish vowels and Finnish length by Japanese and American English listeners and the perception of Arabic consonants by American English listeners. Here are some highlights from our findings so far on the perception of German vowels by American English listeners:
- Free classification, which had previously been used to examine the perceptual similarity of dialects, languages, or non-native accents, is also useful for looking at the similarity of segments. Some nice properties of free classification are that there are no category labels or number of categories imposed by the researcher, and it's possible to analyze which dimensions (e.g. F1, roundedness) listeners are using to categorize the stimuli. Check out our ICPhS 2015 paper on this method.
- Training in linguistics (particularly phonetics/phonology) and knowledge of other languages can affect performance in a free classification task, and even more so in a perceptual assimilation task. Get our slides from New Sounds 2016 here. Email me if you'd like a copy of the manuscript under review.
- In a study together with Meg Cychosz at UC Berkeley, we found that overlap scores from free classification (how often stimuli were grouped together) and overlap scores from perceptual assimilation (how often stimuli were assimilated to the same L1 category) were both good predictors of discrimination in oddity and AXB tasks. However, perceptual assimilation category types (e.g. "two-category," "category-goodness") were not. Results from AXB and oddity tasks were highly correlated with each other (r = .974 for accuracy scores and r = .979 for d'). Get our slides from PSLLT 2017 here.
L2 lexical representations: Alternate or fuzzy?
In previous research (Daidone & Darcy, 2014; Darcy, Daidone, & Kojima, 2013) we've found that learners have difficulty rejecting incorrect pronunciations of words with new phonemes, regardless of whether they can accurately perceive these new sounds. For example, English-speaking learners of German often will accept a non-word with a back vowel as a real word when the real word actually contains a front-rounded vowel, e.g. they will accept [konɪç] as a word when the word is actually könig [kønɪç] 'king.' However, from this research it was unclear if learners' lexical representations were fuzzy or alternate. By fuzzy, we assume that a difficult novel phoneme is underspecified such that the learner would accept many different possible realizations of a word, e.g. könig as [kønɪç], [konɪç], [kunɪç], or even [kenɪç]? If a learner has alternate lexical representations, then we hypothesize that they would only have a limited number of possible realizations that they will accept, e.g. könig only as [kønɪç] or [konɪç]. The current project with Isabelle Darcy, Franzi Kruger, and Ryan Lidster tries to determine which of these two possibilities is true for learners' lexical representations of words containing front-rounded vowels in German.
The effects of input, native-language phonology, and individual differences on lexical representations
Previous research on the lexical encoding of novel L2 contrasts has shown that accurate perception is likely necessary but not sufficient for accurate lexical representations. Even when learners are able to perceptually distinguish L2 sounds, they often struggle with encoding these sounds contrastively in lexical representations, and perception ability has been found to account for only some of the variance in lexical encoding accuracy. In my dissertation I plan to investigate the ability of learners to encode novel words containing the Spanish tap and trill, a contrast that has been shown to be easily discriminable for English-speaking learners and even naïve English listeners, yet difficult for learners to encode accurately in lexical representations. By investigating an easily perceptible contrast, this study will focus on other factors that may explain lexical encoding difficulty beyond perception – unreliable L2 input, the L1 phonological grammar, and learners’ individual differences in cognitive abilities and vocabulary size.