Evaluating contributions of relative vocabulary size and demand for use on masked-speech recognition for bilingual children with normal hearing

Abstract

The Children’s English and Spanish Speech Recognition Test (ChEgSS) is a tool for assessing masked-speech recognition. An audiologist could test a bilingual child’s speech recognition in both English and Spanish, but if time is limited, which language should they choose? We evaluated how two different measures of language dominance, relative demand for use and relative vocabulary size impacted word identification in noise and in a two-talker speech masker for 82 bilingual children (4–17 years) with normal hearing. The participants were exposed to Spanish from birth and varied in their initial exposure to English. Each child completed ChEgSS in English and Spanish using a 4AFC procedure. We measured vocabulary using standardized tests and demand for use using questionnaires. We created language dominance variables by standardizing values then subtracting Spanish scores from English ones. Linear regression evaluated how age and the interaction between length of exposure, relative vocabulary size, and relative language use predicted performance. Relative vocabulary size impacted thresholds, and this effect was larger for children with less exposure in the test language. Results suggest relative vocabulary size and length of exposure should inform the test language(s) used to assess clinical speech recognition.