Previous research demonstrates that simultaneous training of novel sound contrasts in both perception and production can disrupt rather than enhance perceptual learning, indicating that although perception and production are assumed to be closely connected, these modalities may have a competitive relationship. In spite of this perceptual disruption, subjects trained in perception and production show gains in producing the distinction they were trained on, compared to perception-only training. The current study examines how subjects learn to produce a new sound contrast after training in perception or production. L1 Spanish speakers were trained on an unfamiliar Basque sibilant fricative-affricate contrast: /s̺a/–/ʃa/. Since learners’ productions of the contrast may not be identical to the way native speakers distinguish it, and rather than exploring a single phonetic dimension, we apply Linear Discriminant Analysis to acoustic measurements of subjects’ post-test productions to classify whether and how they distinguish the categories in a potentially multidimensional space. This classification model is then applied across conditions to compare production learning across training modes and examine how production learning relates to perceptual learning.

This study investigates the perceptual consequences of nonnative versus native hesitation sounds in evaluating male speech. When the phonetic quality of a hesitation sound is consistent with native speaker hesitation sounds, the hesitation sound is “native.” A hesitation sound with phonetic quality inconsistent with native speaker hesitation sounds is “nonnative.” In Experiments 1A and 1B, participants rated sentences for fluency and accentedness on a Likert scale. In Experiments 2A and 2B, listeners performed a forced choice task to evaluate speech for accentedness and fluency. In Experiments 1A and 1B, hesitation sound phonetic quality did not impact listeners ratings. However, in Experiments 2A and 2B, participants deemed sentences with nonnative hesitation sounds less fluent and more accented compared to those with native hesitation sounds. Results show that the hesitation sound phonetic quality can have perceptual consequences and that the type of task listeners performed to evaluate speech affected accentedness and fluency judgments. This study has important implications for how learners treat pausing when practicing their second language.

Nonnative speech differs from native speech in various ways, including different pausing patterns. There are two types of pauses: filled and unfilled. Unfilled pauses are silent. During filled pauses, speakers make a sound. Different languages use different sounds for filled pauses; this is described as phonetic quality. English speakers use “uh” to hesitate. Spanish speakers use “eh” to hesitate. When the phonetic quality of a hesitation sound is consistent with the hesitation sound used by native speakers, the hesitation sound is “native.” A hesitation sound with phonetic quality inconsistent with a native speaker hesitation sound is “non-native.” Production studies show that proficiency and speech community influence whether second language speakers produce native or nonnative hesitation sounds. However, no study has investigated the perceptual consequences using nonnative versus native hesitation sounds. This study investigates the effect of hesitation sound phonetic quality on perception of language fluency by comparing fluency ratings of sentences with nonnative hesitation sounds to fluency ratings of sentences with native hesitation sounds. This research answers questions such as: Do listeners judge non-native speakers to be less fluent when speakers produce non-native hesitation sounds? Is it beneficial for L2 learners to use native hesitation sounds to achieve perceived fluency?