This study examined longitudinal changes in second language (L2) interlocutors’ mutual comprehensibility ratings (perceived ease of understanding speech), targeting comprehensibility as a dynamic, time-varying, inter action-centered construct. In a repeated-measures, within-participants design, 20 pairs of L2 English university students from different language backgrounds engaged in three collaborative and interactive tasks over 17 minutes, rating their partner’s comprehensibility at 2–3 minute intervals using 100-millimeter scales (seven ratings per interlocutor). Mutual comprehensibility ratings followed a U-shaped function over time, with comprehensibility (initially perceived to be high) being affected by task complexity but then reaching high levels by the end of the interaction. The interlocutors’ ratings also became more similar to each other early on and remained aligned throughout the interaction. These findings demonstrate the dynamic nature of comprehensibility between L2 interlocutors and suggest the need for L2 comprehensibility research to account for the effects of interaction, task, and time on comprehensibility measurements.

When we are born our perceptual systems are capable of discriminating sounds that occur in English, Spanish, Hindi, or any other language. During the first year, our perception begins to zero in on the particular set of sounds that are contrastive in our native language(s) (L1s) (Kuhl et al., 2006). For example, a child whose parents are L1 English speakers will pick up on the fact that /b/ and /p/ are contrastive in English (e.g., “bet” vs. “pet”) and that the major difference is in the burst of air that occurs when the stop is released (i.e., there is a stronger burst of air, or more aspiration, on /p/ than /b/). A child whose parents are L1 Hindi speakers will pick up on this contrast, which also occurs in Hindi, as well as other contrasts that occur in Hindi but not in English. As our perception becomes attuned to our L1(s), we become more sensitive to L1 contrasts, such as /b/ vs. /p/ for L1 English speakers, and less sensitive to non-native contrasts, even though our ability to discriminate non-native sounds remains intact. When we begin to learn another language (L2) later in life, be it through formal instruction at university or through immersion if we move to another country where a different language is spoken, our L1 acts as a filter, altering our perception of L2 sounds. Consequently, we may not detect differences between contrastive L2 sounds that are not contrastive in our L1, and we may fail to notice the difference between our accented pronunciation of the L2 and the target pronunciation.

Significant scholarship has focused on the development of L2 oral skills in naturalistic language learning. However, few studies have examined how instructed learners’ pronunciation develops over time, despite the importance of the classroom context. This study addressed this gap by investigating L2 Spanish learners’ comprehensibility and accentedness over a yearlong period. Twenty-six learners completed a sentence-building task on five occasions distributed throughout their second, third, and fourth semesters of college-level Spanish language instruction. Learners received 20 sets of images, combining the images in each set to form a simple sentence in Spanish. Eighteen native Spanish listeners rated learners’ recordings for comprehensibility and accentedness using 9-point Likert scales, and mixed-effects models were fit to the ratings data using R. Learners were rated as quite comprehensible despite the presence of a moderate to strong foreign accent. Although both comprehensibility and accentedness improved over time, rates of change varied. Comprehensibility improved quickly but was subject to greater deceleration in rate of change over time. In contrast, accentedness improved steadily and did not exhibit the same degree of flattening as comprehensibility. These results intersect with work on naturalistic learners and suggest that pronunciation development may be characterized by phases of change.

This study investigated relationships among intelligibility, comprehensibility, and accentedness in the speech of L2 learners of Spanish who completed a prompted response speaking task. Thirty native Spanish listeners from Spain were recruited through Amazon Mechanical Turk to transcribe and rate extracted utterances, which were also coded for grammatical and phonemic errors, and speaking rate. Descriptively, although most utterances were intelligible, their comprehensibility and accentedness varied substantially. Mixed-effects modeling showed that comprehensibility was significantly associated with intelligibility whereas accentedness was not. Additionally, phonemic and grammatical errors were significant predictors of intelligibility and comprehensibility, but only phonemic errors were significantly related to accentedness. Overall, phonemic errors displayed a stronger negative association with the listener-based dimensions than grammatical errors. These findings suggest that English-speaking learners of Spanish are not as uniformly intelligible and comprehensible as FL instructors might believe and shed light on relationships among speech constructs in an L2 other than English.

As Derwing (2010) observed nearly ten years ago, one of the goals of pronunciation research is to identify how different aspects of second language (L2) speech develop over time, providing teachers with information on the pronunciation problems that will work themselves out, versus those that will likely pose an ongoing challenge. At the same time, research must account for the cognitive, socio-affective, and experiential variables that shape pronunciation learning outcomes (Moyer, 2014a, 2014b).

In Spanish, voiced stops weaken to approximants and display variables degrees of lenition according to the context in which the stop occurs, making them a complex pronunciation feature. Accumulated findings from cross-sectional research on second language (L2) speakers suggests that many L2 learners struggle to produce the approximants even at the most advanced levels of study. The present study offers a new perspective on the approximants by studying individual learners’ production of Spanish [β] over time and across phonetic contexts. Twenty-six English speaking learners of L2 Spanish recorded two speaking tasks five times over a yearlong period corresponding to their second and third semesters of college-level language instruction. Mixed effects models were fit to learners’ C:V intensity ratio data to examine development, and stress and task type were included as substantive predictors. Although the group trajectory was flat, many learners displayed substantial change over time, including positive and negative trajectories.

Longitudinal research on second language (L2) sound learning demonstrates that speakers’ production of challenging L2 sounds can improve in the absence of targeted instruction. Although the growing body of longitudinal work on this topic provides insight into the rate and shape of development, the factors that shape L2 phonetic production in spontaneous speech are not yet well understood. The data described here are part of a longitudinal data set collected from native English speakers enrolled in introductory-level Spanish language courses. For the current analysis, 16 participants were selected based on the availability of data coinciding with the beginning and end of the first semester and end of the second semester. Participants completed a simplified picture description task. Voice Onset Time (VOT) was annotated and measured for all instances of Spanish /p, t, k/ in the speech samples. Participants’ instructors were recorded during two class periods. Recordings were transcribed and a frequency measure was calculated based on the resulting teacher speech data. After controlling for a range of linguistic factors known to affect VOT, modeling demonstrated that time and frequency were not significantly related to VOT.

This study examined relationships between language learning motivation and the longitudinal development of second language (L2) pronunciation. Twenty-six English-speaking learners of Spanish recorded a simplified picture description task five times over a yearlong period spanning their second, third, and fourth semesters of Spanish language instruction. Learners also completed a quantitative motivation survey based on the L2 Motivational Self System and an open-ended questionnaire on their language learning beliefs once per semester, yielding three measurements. Eighteen native Spanish listeners rated learners’ clips for comprehensibility and accentedness. Although mixed modeling of the motivation data revealed a slightly negative trajectory for motivational subcomponents, qualitative analyses of individual patterns indicate that learners were beginning to formulate and evaluate language learning goals that were set into a larger framework of personal and professional objectives. Mixed effects models of the pronunciation data demonstrate that both comprehensibility and accentedness improved over time. When the quantitative motivation measures were integrated into the modeling process as time-varying fixed effects, effort was significantly related to accentedness, which suggests that effort may have played an increasingly important role in shaping learners’ pronunciation over time.

Despite intuitive and theoretically motivated claims that Study Abroad (SA) is an optimal environment for language development, including pronunciation gains, research on its effectiveness has produced contradictory results. Furthermore, there is little known about short-term study abroad programs, where matriculation numbers are increasing faster than ever before. This chapter analyzes pre- and post-SA oral production data from 18 advanced learners of Spanish, focusing on stop consonants (/p, t, k, b, d, g/). Development was defined in terms of voice onset time for /p, t, k/ and a 5-point lenition measure for /b, d, g/. Learners produced significantly shorter VOT values after the SA program, though there was not a similar improvement in lenition score. Therefore, the intensive, six-week SA experience yielded substantial gains in L2 pronunciation for these advanced learners of Spanish. Results are discussed in light of advances in both research methodology and study abroad program design.