Training new, nonnative speech contrasts: A comparison of the prototype and perceptual fading techniques.

262

205

Behavioral perceptual abilities and neurophysiologic changes observed after listening training can generalize to other stimuli not used in the training paradigm, thereby demonstrating behavioral “transfer of learning” and plasticity in underlying physiologic processes. Nine normal-hearing monolingual English-speaking adults were trained to identify a prevoiced labial stop sound (one that is not used phonemically in the English language). After training, the subjects were asked to discriminate and identify a prevoiced alveolar stop. Mismatch negativity cortical evoked responses (MMN) were recorded to both labial and alveolar stimuli before and after training. Behavioral performance and MMNs also were evaluated in an age-matched control group that did not receive training. Listening training improved the experimental group’s ability to discriminate and identify an unfamiliar VOT contrast. That enhanced ability transferred from one place of articulation (labial) to another (alveolar). The behavioral training effects were reflected in the MMN, which showed an increase in duration and area when elicited by the training stimuli as well as a decrease in onset latency when elicited by the transfer stimuli. Interestingly, changes in the MMN were largest over the left hemisphere. The results demonstrate that training can generalize to listening situations beyond those used in training sessions, and that the preattentive central neurophysiology underlying perceptual learning are altered through auditory training.

Section: Plasticity Of the Adult Systemmentioning

confidence: 99%

Central auditory system plasticity: Generalization to novel stimuli following listening training

Tremblay

Kraus

Carrell

et al. 1997

262

205

“…As a result, the trainees were able to learn to discriminate the training stimuli but were not able to transfer this learning to new stimuli and contexts. In more recent attempts at L2 training, it has become clear that added variance in the training set ͑e.g., more speakers, more phonetic contexts͒ aids learning and generalization ͑Bradlow et al Jamieson and Morosan, 1989;Lively et al, 1993͒. It is quite possible that a major benefit of high-variability training is that less informative cues will vary more within a category across multiple exemplars while more informative cues will be relatively more stable.…”

Section: A Implications For L2 Phonetic Acquisitionmentioning

confidence: 99%

Cue weighting in auditory categorization: Implications for first and second language acquisition

Holt

Lotto

2006

254

274

The ability to integrate and weight information across dimensions is central to perception and is particularly important for speech categorization. The present experiments investigate cue weighting by training participants to categorize sounds drawn from a two-dimensional acoustic space defined by the center frequency ͑CF͒ and modulation frequency ͑MF͒ of frequency-modulated sine waves. These dimensions were psychophysically matched to be equally discriminable and, in the first experiment, were equally informative for accurate categorization. Nevertheless, listeners' category responses reflected a bias for use of CF. This bias remained even when the informativeness of CF was decreased by shifting distributions to create more overlap in CF. A reversal of weighting ͑MF over CF͒ was obtained when distribution variance was increased for CF. These results demonstrate that even when equally informative and discriminable, acoustic cues are not necessarily equally weighted in categorization; listeners exhibit biases when integrating multiple acoustic dimensions. Moreover, changes in weighting strategies can be affected by changes in input distribution parameters. This methodology provides potential insights into acquisition of speech sound categories, particularly second language categories. One implication is that ineffective cue weighting strategies for phonetic categories may be alleviated by manipulating variance of uninformative dimensions in training stimuli.

“…For example, Lively, Logan, and Pisoni (Lively et al, 1993) found that Japanese listeners trained to identify /r/ and /l/ in one talker's voice did not improve in identifying /r/ and /l/ produced by an unfamiliar talker, whereas listeners trained on multiple talkers did. Such studies have established that careful selection of varied phonetic tokens facilitates the generalization of perceptual training over a closed stimulus set in adults (Bradlow et al, 1996;Jamieson and Morosan, 1989;Logan et al, 1991). Pisoni (1992) suggests that variation provides insight into invariant features.…”

Section: Introductionmentioning

confidence: 99%

Overnight consolidation promotes generalization across talkers in the identification of nonnative speech sounds

Earle

Myers

2014

This investigation explored the generalization of phonetic learning across talkers following training on a nonnative (Hindi dental and retroflex) contrast. Participants were trained in two groups, either in the morning or in the evening. Discrimination and identification performance was assessed in the trained talker and an untrained talker three times over 24 h following training. Results suggest that overnight consolidation promotes generalization across talkers in identification, but not necessarily discrimination, of nonnative speech sounds.