Risk factors for pregnancy among rural and urban-dwelling adolescents in a high adolescent-pregnancy setting; a case control study.

In the field of second language (L2) speech acquisition, dominant theoretical frameworks regard cross-language phonetic similarity as a critical factor for predicting and explaining L2 acquisition performance. Key examples include the Speech Learning Model and its revision (SLM/SLM-r; ), the Perceptual Assimilation Model for L2 learners (PAM-L2; ), and the Second Language Linguistic Perception model (L2LP; ). To determine cross-language phonetic similarity, , p. 172) summarized four techniques commonly employed in recent L2 speech perception research: (1) qualitative descriptions of articulatory-phonetic similarities; (2) qualitative perceptual comparisons involving the (narrow) transcription of L2 segments; (3) acoustic comparisons of native language (L1) and L2 phones, including the use of correlational techniques such as discriminant analysis; and (4) direct measures of perceived/perceptual similarity, which involve presenting L2 segments for listeners to categorize in terms of L1 phonetic categories. However, recent research suggests that direct measures of perceptual similarity are not always predictable from acoustic comparisons (cf. , ). Thus, direct perceptual measures represent a more valid approach for determining L1/L2 perceived similarities for both naïve listeners and L2 learners. , , and , p. 54) argue that learners’ perceptual assimilation patterns provide the most accurate reflection of cross-language phonetic similarity. The associated experimental methodology is known as the Perceptual Assimilation Task (PAT). The PAT has been extensively utilized in numerous studies (e.g., ; ; ; ; ; , ; ). While specific implementation procedures vary across the literature, three primary paradigms have emerged: The first paradigm requires participants to provide a native orthographic symbol for each non-native stimulus, thereby yielding information regarding the mapping between phonetic stimuli and L1 phonemic categories.