By Jay R. Lucker, EdD, CCC-A/SLP, FAAA; Cydney Fox, AuD; and Bea Braun, AuD
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Auditory processing disorders (APD) in school-age children can lead to learning problems.1 Audiologists may determine the presence or absence of APD in this population and make specific therapeutic recommendations. However, many therapies for APD have not been peer-reviewed or examined with statistical analysis to determine efficacy. The present study evaluates a therapeutic option called CAPDOTS-Integrated (also referred to as CAPDOTS), an online training program that aims to improve dichotic listening problems.
According to Jerger, “Dichotic listening (DL) tests are at the core of the diagnostic evaluation of auditory processing disorder... [Such tests] have been used for decades both as screening tools and as diagnostic tests in APD evaluation."2 Thus, audiologists evaluating school-aged children for APD may find these children to have dichotic listening problems. Those diagnosed with dichotic listening problems are recommended to try a dichotic listening training program, such as CAPDOTS-Integrated.1 Presently, CAPDOTS-Integrated claims to treat binaural auditory integration problems known as dichotic listening difficulties. CAPDOTS is a treatment program requiring access to the internet and good quality headphones. It can be completed in the trainer's office, at school, or home.1 On their website, it states that CAPDOTS–Integrated “improves the ability to follow complex, multi-step directions, listening attention especially in distracting background noise, inferential listening and understanding of group instructions, auditory memory, academic performance especially for reading comprehension and spelling."1 However, one may ask what evidence supports these claims?
EVALUATING THE SUPPORTING RESEARCH
The CAPDOTS website cites two conference handouts on the changes after CAPDOTS training. Carol A. Lau discussed mid-latency, electrophysiological responses in two subjects.2 The 27-year-old subject identified as diagnosed with “binaural integration deficit" only completed 80 percent of the CAPDOTS training. The 16-year-old subject is reported diagnosed with a binaural integration (dichotic listening) auditory processing disorder. Results of mid-latency electrophysiological measures revealed increased response findings after these subjects completed CAPDOTS. Qualitative data discusses the Na-Pa amplitude changes and percent differences for each subject. Statistical analyses were not used so there is no indication whether these changes were significant.
The second conference presentation, also by Carol Lau, used only three subjects, all identified as having auditory processing problems based on scores from the SCAN and Dichotic Digits Tests.4 Number values are the only results provided. There were no statistical analyses discussed.
A third reference is an article published in The Hearing Journal on a study involving three adults identified with co-morbid peripheral hearing loss and CAPD.5 Each subject was used as a single case study presenting results of auditory processing tests pre- and post- CAPDOTS training. Findings identified improvements after CAPDOTS training, but no statistical analyses were provided.
Another study published in 2013 used individual case presentations including one of a second-grade boy with auditory processing problems, an older adult who suffered a head injury, a preteen with no history of educational or auditory processing concerns, two girls identified by qualitative observations having problems following verbal interactions and directions, and an adult with a history of learning disabilities.6 All subjects were evaluated using the SCAN test as well as Dichotic Digits. Data compared pre- and post- CAPDOTS training with improvements noted, but no statistical analyses were provided.
PURPOSE OF THE PRESENT STUDY
Studies have looked at changes in auditory processing after completing CAPDOTS training. However, none provides statistical analyses, and all use small samples. The present looked at a large sample of children and adolescents diagnosed with APD. The researchers measured what changes occur when statistical analyses are used. The research questions asked whether auditory processing test findings revealed significant improvements after completing CAPDOTS training, and for what specific measures, as well as investigating the degree of improvement following training.
Forty-six children and adolescents (26 males and 20 females) participated in the study. Two of the authors (CF and BB), both licensed clinical audiologists, evaluated participants identifying all having significant APD. Participants ranged from 6 years to 18 years with a mean age of 10.0 years (standard deviation of 2.70 years). Participants had normal hearing which would not influence their auditory processing or treatment.
Auditory Processing Tests: Auditory processing was assessed via the SCAN-3 C for children7 and A for adolescents8 Dichotic Digits (DDT),9 Frequency Patterns and Duration Patterns,10 Competing Sentences,11 Low Pass Filtered Speech,12 SSW Test,13 and the Phonemic Synthesis Test (PST),14 using the specific scores for each ear or individual measure on the tests.
CAPDOTS Training: CAPDOTS is a web-based therapy based on a Staggered Dichotic Listening Training (SDLT) paradigm, using words, digits, and syllables. SDLT uses a difference in the timing presentation of targets in each ear starting with a gap between stimuli presented to each ear with the gap decreasing until the two stimuli are presented simultaneously.
Participant CAPDOTS therapy at home with monitoring by the audiologist. Upon completion of CAPDOTS training, the auditory processing evaluation was re-administered. Thus, pre- and post- training scores were available and were compared allowing for statistical analyses of the data.
Data Analyses: A paired (also called dependent) samples t-test was calculated for each measure. Performance for the right ear was compared separately from performance for the left ear when appropriate. -test scores yielding probability values less than 0.05 identified that the change was significant. Significant t-test findings were then evaluated by Cohen's d.
RESULTS & DISCUSSION
A total of 24 measures were completed in the study. Table 1 presents the results of the pre- and post- CAPDOTS measures, indicating large differences between the post- and pre-therapy findings.
Table 2 shows the t-test statistical analyses results, which reveal significant findings for 16 of the 24 measures. Only one dichotic measure (Right Ear for Competing Words-Directed Ear Right Ear First) was not significant. The remaining 7 dichotic measures were significant. Thus, significant findings were found for 7 of the 8 dichotic measures of auditory processing.
Surprisingly, CAPDOTS training not only significantly improved dichotic listening but also made significant improvements in other areas of auditory processing. Nine measures were also found to have significant t-test results. Therefore, the present study indicates that CAPDOTS therapy can show significant improvements in dichotic listening as well as in other areas of auditory processing.
To determine how much change was found after CAPDOTS training, a post hoc analysis was conducted for the 16 significant measures found. This analysis determined the effect size of change using Cohen's d for dependent samples. Table 3 presents the results of these calculations.
Cohen's d values range from no significant effect (less than .20) to a small effect (from .20 to .49), a medium effect (from .50 to .79), a large effect (from .80 to 1.0), and very large effect (greater than 1.0). These values are measures of the number of standard deviation change occurring. A review of Table 3 indicates that only one measure revealed a small improvement and three showed a medium improvement. Large improvements were found for six measures and very large improvements for six other measures. Thus, the majority of improvements were found to be large and very large.
Results of the present study indicated significant improvements in dichotic listening with 7 of the 8 measures showing large and very large effect sizes. What was surprising was that 9 non-dichotic measures of auditory processing revealed significant changes after CAPDOTS therapy. Thus, the conclusion drawn is that CAPDOTS therapy not only can make a significant improvement in dichotic listening but can also change other auditory processing factors. Changes were found in auditory temporal processing (Frequency Patterns and Time Compressed Sentences for each ear), understanding distorted speech (Filtered Speech), and auditory phonological processing (Phonemic Synthesis). Thus, professionals recommending CAPDOTS training for children and adolescents with auditory processing disorders should not only expect improvement in dichotic listening and auditory integrative processing but also in other areas identified above.
One important outcome from the present study relates to what is stated on the CAPDOTS website1 that CAPDOTS training should lead to improvements in a variety of areas which include listening in noise, understanding verbal messages in groups (which may relate to listening in noise), reading and spelling abilities. The findings from the present evaluation indicated significant improvements in auditory phonological processing which would be related to reading decoding and spelling abilities. However, no improvements were evidenced for listening in noise. Results of the Auditory Figure-Ground measures used were not significant (p>0.05) for either the right or left ears. Although the CAPDOTS website does not address auditory temporal processing skills which are important, the results of the present study indicate significant improvements in this auditory process. Perhaps this is due to the subject's ability to more rapidly process (time compression) and be better able to understand the prosodic features of the verbal message (frequency pattern processing). Additionally, integrative processing (dichotic listening) can contribute to other aspects of listening because it involves processing the meaning of what is spoken to the listener.
LIMITATIONS & FUTURE RESEARCH
As with any study, there can be limitations leading to recommendations for further research. One limitation could be considered the number of participants used. This study included 46 participants all identified with auditory processing disorders. However, the specifics of each participant's auditory processing issues were not identified. Some participants might have had additional issues such as attention disorders (ADHD) or autism spectrum disorder (ASD) that were not identified. However, if participants had ADHD or ASD, findings from the present study suggest that even for people with these diagnoses, CAPDOTS therapy might be beneficial in improving their auditory processing abilities. Further research may wish to look at subjects diagnosed with ADHD or with ASD and compare these participants with subjects not found to have neither of these psychological issues.
Another limitation of the present study relates to the specific auditory processing tests used. Other tests used by audiologists may need to be statistically evaluated to determine if there are significant changes following CAPDOTS training. Areas such as auditory (listening) attention were not evaluated. It would be interesting to see what changes might occur on a measure of auditory attention such as the Auditory Continuous Performance Test (ACPT)15 following CAPDOTS therapy.
One other limitation of the present study relates to age. Participants were children from 6 to 12 years old as well as adolescents from 13 to 18 years old. It is likely that children performed differently from adolescents. Thus, future research may wish to compare findings for children versus adolescents to determine if differences may be found based on age.
Whatever the limitations, the present investigation looked carefully at a large group of children and adolescents who completed CAPDOTS-Integrated training online. The findings indicated very significant changes in dichotic listening as well as in other areas of auditory processing not specific to dichotic listening. The conclusion is that after CAPDOTS training, one should expect to see significant improvements in various aspects of auditory processing.
ABOUT THE AUTHORS: JAY R. LUCKER, EDD, CCC-A/SLP, FAAA, is a professor and the director of the five-year accelerated master's degree program in the department of communication sciences and disorders at Howard University in Washington, DC. He also has a part-time private practice specializing in issues related to auditory processing disorders. CYDNEY FOX, AUD, is a member of the Craniofacial Team at Orthopaedic Hospital and a full-time audiologist at Audiology Solutions LA. BEA BRAUN, AUD, is a clinical audiologist and a credentialed educational audiologist. She founded the Auditory Processing Center of Pasadena.
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3. Lau C (2016a). Auditory Mid-Latency Response (AMLR) Pre- and Post- Dichotic ListeningTraining Using CAPDOTS. https://capdots.com/wp-content/uploads/2017/10/DichoticListening_HandoutWeb.pdf
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