This study investigated the roles of cross-language transfer of first language (L1) and attentional control in second-language (L2) speech perception and production of sequential bilinguals, taking phonological overlap into account.
Twenty-five monolingual Dutch-speaking and 25 sequential bilingual Turkish–Dutch-speaking 3- and 4-year-olds were tested using picture identification tasks for speech perception in L1 Turkish and L2 Dutch, single-word tasks for speech production in L1 and L2, and a visual search task for attentional control. Phonological overlap was manipulated by dividing the speech tasks into subsets of phonemes that were either shared or unshared between languages.
In Dutch speech perception and production, monolingual children obtained higher accuracies than bilingual peers. Bilinguals showed equal performance in L1 and L2 perception but scored higher on L1 than on L2 production. For speech perception of shared phonemes, linear regression analyses revealed no direct effects of attention and L1 on L2. For speech production of shared phonemes, attention and L1 directly affected L2. When exploring unshared phonemes, direct effects of attentional control on L2 were demonstrated not only for speech production but also for speech perception.
The roles of attentional control and cross-language transfer on L2 speech are different for shared and unshared phonemes. Whereas L2 speech production of shared phonemes is also supported by cross-language transfer of L1, L2 speech perception and production of unshared phonemes benefit from attentional control only. This underscores the clinical importance of considering phonological overlap and supporting attentional control when assisting young sequential bilinguals' L2 development.
Chinese-speaking older adults usually do not perceive a hearing problem until audiometric thresholds exceed 45 dB HL, and the audiometric thresholds of the average hearing-aid (HA) user often exceed 60 dB HL. The purpose of this study was to examine the relationships between cognitive and hearing functions (measured as audiometric or speech reception thresholds) in older Chinese adults with HAs and with untreated hearing loss (HL). Participants were 49 Chinese older adults who used HAs and had moderate to severe HL (HA group), and 46 older Chinese who had mild to moderately severe HL but did not use HAs (untreated; or UT group). Multiple linear regression analysis was employed to evaluate how well age, education level, audiometric thresholds, and speech perception in noise were related to performance on general cognitive function, working memory, executive function, attention, and verbal learning tests. Results showed that speech perception in noise alone accounted for 13–25% of the variance in general cognitive function, working memory, and executive function in the UT group, and 9–21% of the variance in general cognitive function and verbal learning in the HA group (i.e., medium effect sizes). Audiometric thresholds did not explain any proportion of the variance in cognitive functioning in the HA or UT group. Thus, speech perception in noise accounts for more variance in cognitive performance than audiometric thresholds, and is significantly associated with different cognitive functions in older Chinese adults with HAs and with untreated HL.