Auditory processing disorder (APD) is a disorder caused by a disruption within the
central auditory pathway that impairs processing of complex or degraded auditory inputs.
Patients with this condition often present with normal hearing but still report problems
understanding speech. This commonly manifests as individuals having difficulty
understanding speech in challenging listening environments (e.g., noisy backgrounds,
reverberant environments, rapid speech), localizing sounds, and following complex
auditory directions. An underlying auditory skill vital to these processes is binaural
processing, or the ability to utilize auditory cues from both ears. Binaural processing
aids in identifying a talker in the midst of background noise and allows us to better
separate relevant from irrelevant inputs.
While auditory processing evaluations assess specific auditory skills (like binaural
processing) necessary for efficient processing and understanding of complex auditory
signals, many of the tests rely heavily on language. This poses an issue for individuals
for whom English is not their native language. Because the tests are linguistically
loaded, the obtained results do not clearly identify whether an issue should be
attributed to a central auditory problem or to the language used in the test materials.
Thus, audiologists are often hesitant to test bilingual patients who demonstrate features
of APD.
It is possible that bilingual individuals would perform more favorably when tested in
their native language (L1). Indeed, differences in complex auditory task performance have
been seen in Spanish-English bilinguals when materials were presented in Spanish versus
English. Recent studies have evaluated test-language effects in bilingual education and
described significant improvements in performance when bilinguals were instructed and
tested in their native language (L1) compared to performance in their later acquired
language (L2). Numerous studies have also assessed monolingual vs. bilingual performance
in complex auditory tasks including listening in noise, auditory memory, and competing
speech. While much research in auditory processing of bilingual speakers compares
performance between monolinguals and bilinguals, evidence to inform best clinical
practice in the assessment of APD in bilinguals is lacking. To date, relatively few
studies investigate performance within the same participant with testing language being
the differential factor.
Therefore, the purpose of this study is to compare binaural processing performance in
Spanish-English bilingual participants when tested in Spanish (L1) versus in English
(L2). Based on prior literature, we suspect that bilingual participants will perform
better when they are instructed and presented with assessments in their native language
versus when they are assessed in their later acquired language (L2). However, it is
possible that our participants, who will be proficient in both L1 and L2, will show no
difference in task performance. Regardless, by comparing binaural processing performance
in bilingual participants, we will clarify whether testing bilingual individuals in a
secondary language (when proficient in that language) results in valid and reliable
measures of their auditory processing abilities. Thus, our results will provide evidence
to establish best clinical practice when evaluating bilingual listeners for auditory
processing deficits. This will enable clinicians to more confidently evaluate and
diagnose auditory processing disorders in bilingual populations.
