Comparing Central Auditory Processing Performance in Bilinguals Using L1 vs. L2 Materials
Phase: NA
Conditions: Auditory Processing Disorder
Sponsor: University of Arkansas

Title:  Comparing central auditory processing performance in bilinguals using L1 vs. L2 materials 
NCT #: NCT05452486 
Date:  10/23/2023 
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Study Title: 
Comparing central auditory processing performance in 
bilinguals using L1 vs. L2 materials 
 
 
Study Investigators:  
Caitlin Price, Au.D., Ph.D. 
 
Ana Miller, B.S. 
 
 
Charia Hall, Au.D. 
 
 
 
Study location: 
UAMS CHP Speech and Hearing Clinic 
 
 

Title:  Comparing central auditory processing performance in bilinguals using L1 vs. L2 materials 
NCT #: NCT05452486 
Date:  10/23/2023 
Page 2 
Study Protocool 
The proposed study is a repeated measures experimental design in which participants will 
complete prescreening measures and APD tests in both English (L2) and Spanish (L1). 
Participants’ performance on APD tests will be compared between L1 and L2 to determine if 
the language used in the test materials impacts auditory processing performance. 
Upon arrival participants will complete the consent process in which the PI will describe in 
detail all study procedures, risks and benefits of the study, and the lack of negative 
consequences should the participant choose to withdraw from the study or cease 
participation during data collection. Once the consent form has been signed, the participant 
will complete a basic hearing evaluation to ensure all inclusion criteria are met. This will 
include:  
• 
Otoscopy - to ensure normal external ear anatomy and no visual abnormalities, 
infection, or damage are present in the external ear or eardrum 
• 
Tympanometry - to assess middle ear health and function 
• 
Air and bone conduction - to assess hearing sensitivity across a range of 
frequencies (i.e., octave frequencies from 250-8000 Hz)  
• 
Speech recognition threshold (SRT) - to determine the lowest level at which the 
participant can recognize and repeat a two-syllable word accurately   
If during the hearing evaluation a hearing loss is found, the participant will be appropriately 
counseled regarding the hearing loss and referred for diagnostic testing. These individuals 
will not qualify to participate in this study.  
Language proficiency in both Spanish and English will be assessed via questionnaire and 
an online proficiency test offered by Transparent Language 
(https://www.transparent.com/learn-spanish/proficiency-test.html). These proficiency tests 
will assess grammar, vocabulary, and reading comprehension in each language. To be 
considered proficient in a given language, participants must score above 80% on the 
assessment (Mendel & Widner, 2016).  
If a participant meets all inclusion criteria (normal results for all above-mentioned tests and 
below-specified demographics), auditory processing tests will be completed. Each 
participant will be tested twice, once in Spanish and once in English, using dichotic digits, 
competing words, and competing sentences (scoring sheets included). Descriptions of 
these tests are as follows: 
• 
Dichotic digits. This test is a binaural integration task to assess the patient’s ability to 
integrate information being presented to both ears. During this test, the participant 
will be presented with four numbers (1-10 excluding 7), two in each ear 
simultaneously. The participant will be asked to repeat all four numbers; the order of 
repetition is not important.  
• 
Dichotic word listening test (DWLT). During this test, two words are presented, one 
in each ear. The participant is instructed to repeat the word presented at the target 
ear (specified in test instructions), while they ignore the word in the opposite ear. 
This is an assessment of the participant’s ability to separate relevant information 
from unwanted, distractor information. The word presented in the target ear will be 
presented at a lower presentation level than the word presented in the opposite ear.  

Title:  Comparing central auditory processing performance in bilinguals using L1 vs. L2 materials 
NCT #: NCT05452486 
Date:  10/23/2023 
Page 3 
• 
Synthetic sentence identification (SSI) test. During this test, two complete sentences 
are presented, one in each ear. The participant is instructed to only repeat the 
sentence presented at the target ear (specified in test instructions), while they ignore 
the sentence in the opposite ear. The sentence in the target ear is presented at 35 
dB SL, while the ignored sentence is presented at 50 dB SL. This assesses the 
participant’s ability to separate information coming into both ears and the ability to 
ignore unwanted information.  
The presentation of the Spanish and English test materials will be counterbalanced across 
participants to minimize fatigue and practice effects. Following completion of tests, the test 
results will be discussed with the patient. If any indication of hearing loss or auditory 
processing deficits are identified, the participant will be notified and appropriate 
recommendations for more thorough evaluations and treatment will be provided. 
Data Analysis 
Mixed linear regression models will be used to evaluate performance differences between 
L1 and L2 on APD assessments. Post-hoc adjustments will be used to correct for multiple 
comparisons. Correlations will also be conducted to investigate relationships between 
auditory processing performance and demographic variables including language 
proficiency.  
Based on the proposed analyses, an a priori power analysis was conducted to estimate the 
required sample size. The power analysis (t-test estimates, 2-tailed, α = 0.05, power = 0.90; 
G*Power 3.1; Faul et al., 2007) revealed a sample size of 19 participants would be sufficient 
to detect large effect sizes (d = 0.8), similar effects as reported in studies using similar 
paradigms (Desjardins et al., 2019; Lopez et al., 1997).