How Noise and Language Proficiency Influence Speech Recognition by Individual Non-Native Listeners

Abstract

This study investigated how speech recognition in noise is affected by language proficiency for individual non-native speakers. The recognition of English and Chinese sentences was measured as a function of the signal-to-noise ratio (SNR) in sixty native Chinese speakers who never lived in an English-speaking environment. The recognition score for speech in quiet (which varied from 15%–92%) was found to be uncorrelated with speech recognition threshold (SRTQ /2), i.e. the SNR at which the recognition score drops to 50% of the recognition score in quiet. This result demonstrates separable contributions of language proficiency and auditory processing to speech recognition in noise.

How Age and Linguistic Competence Affect Memory for Heard Information

“…Word recognition has been found to be poorer in young people when they are listening to speech in their second language under noisy conditions (e.g., Bradlow and Pisoni, 1999 ; Ezzatian et al, 2010 ). Here, the reasons for needing a more favorable SNR are unlikely to be due to an impoverished acoustic signal but rather to an inadequate command of the phonology, semantics, and syntax of their second language (Gollan and Kroll, 2001 ; Bialystok et al, 2009 ; Zhang et al, 2014 ). Moreover, when English is a person's second language, it is possible that an English word might elicit activity in both the L2 and L1 lexicons, leading to some degree of confusion (Kroll and Steward, 1994 ).…”

“…Although the present study equated young EL1 and young EL2 listeners with respect to word recognition, it did not compensate for their poorer semantic and linguistic skills, slower lexical access, and possible cross-language interference. As Zhang et al ( 2014 ) pointed out, the relatively poorer 50% speech recognition thresholds of EL2 listeners whose asymptotic performance in quiet is near perfect, most likely reflects their lack of proficiency in the second language. Because in the current set of experiments, individually adjusting the SNRs at which the to-be-remembered words were presented produced near-asymptotic word recognition performance in all listeners, we would expect Zhang et al's argument to hold and the word recognition thresholds of EL2 listeners in this experiment to depend primarily on their proficiency in their second language (Gollan and Kroll, 2001 ; Bialystok et al, 2009 ; Zhang et al, 2014 ).…”

“…As Zhang et al ( 2014 ) pointed out, the relatively poorer 50% speech recognition thresholds of EL2 listeners whose asymptotic performance in quiet is near perfect, most likely reflects their lack of proficiency in the second language. Because in the current set of experiments, individually adjusting the SNRs at which the to-be-remembered words were presented produced near-asymptotic word recognition performance in all listeners, we would expect Zhang et al's argument to hold and the word recognition thresholds of EL2 listeners in this experiment to depend primarily on their proficiency in their second language (Gollan and Kroll, 2001 ; Bialystok et al, 2009 ; Zhang et al, 2014 ). The fact that episodic memory did not appear to differ with language competence when the listening situation was adjusted to produce equivalent word recognition suggest that the primary factor that makes it difficult for young EL2 listeners to recall heard words in noisy everyday listening situations is their poorer word recognition when they are tested at the same level as EL1 listeners, and not their poorer command of L2.…”

“…Previous studies have shown that the psychometric functions relating percent correct word recognition to SNR have equivalent slopes for younger and older adults (Ben-David et al, 2012 ), and that the slopes for younger adults do not differ substantially for EL1 and EL2s (Zhang et al, 2014 ). Hence, once the SNRs are individually adjusted for 50% word recognition, changes away from the adjusted value should produce equivalent performance across age and language experience in the absence of contextual support.…”

Effects of Semantic Context and Fundamental Frequency Contours on Mandarin Speech Recognition by Second Language Learners

“…Only when all the phonological features, i.e., consonant, vowel and tone were correctly identified, the answer was considered correct. Speech recognition accuracy was determined by a keyword-correct count ( Scott et al, 2004 ; Wang et al, 2013 ; Zhang et al, 2014 ). The number of keywords (content words, varied across sentences from 3 to 5) identified correctly by each listener was counted and then converted to the percentage of the total number of words and averaged across listeners.…”