Auditory processing disorder (APD) refers to difficulties in processing auditory information in the central nervous system, affecting approximately two to seven percent of the population.1,2 Individuals with APD, despite having normal hearing, may exhibit difficulty in receiving, organizing, and understanding speech, which can be associated with language learning difficulties.3 The symptomatology of APD is broad since it varies considerably from person to person.
Various screeners are used to identifying individuals who are at risk of APD. These screeners are essential as they encourage early identification and indicate the need for further diagnostic testing, thereby reducing the number of unnecessary referrals.4 They also provide preliminary information about auditory behaviors, listening skills, and communication abilities. APD screeners, which can be administered by teachers, parents, speech-language pathologists, audiologists, or psychologists,5,6 are broadly classified as either questionnaire- or performance-based tools. Questionnaire-based screening checklists filled by parents and professionals help paint an overall picture of an individual's listening behavior and educational and social development.3 Since these screeners provide an extensive background of the individual, it also helps identify possible comorbid conditions associated with APD. Performance-based screening tests evaluate an individual's functional listening deficits with the help of various recorded tests, including temporal processing, dichotic listening, and listening-in-noise.7 During screening, the individual is presented with recorded stimuli via headphones and has to respond as instructed.
Questions have been raised about the effectiveness of commonly used APD screeners in accurately identifying at-risk individuals.8-11 As questionnaire-based checklists may include questions that are not specific to APD, it can lead to over-referral of individuals with non-auditory problems. The validity of performance-based tests has been questioned as findings of these tests can be affected by the higher cognitive functions such as working memory.12,13 The challenges with APD screening procedures include the lack of a universally accepted screening method and the limited information available about the ability of screeners to predict the diagnosis of APD.
This study retrospectively reviewed the medical records of 85 individuals (median age = 10; female = 39) assessed for APD at Bloomsburg University's Clinic for Hearing and Balance (BUCHB) from 2010 to 2018. All participants had normal hearing sensitivity, normal middle ear function, and no history of known neurological or psychological conditions. English was their first language. The audiological evaluations considered case history, otoscopy, pure tone and speech audiometry, tympanometry, and acoustic reflexes testing. The questionnaire-based screening tools included the Buffalo Model Questionnaire-Revised (BMQ-R), the Children's Auditory Performance Scale (CHAPS), and Fisher's Auditory Problems Checklist (FAPC). The performance-based tests used were the SCAN-3: Auditory Figure Ground (AFG), Competing Words Free Recall (CW-FR), and Gap Detection Test (GDT).
The participants assessed for APD were given a combination of the following tests: Dichotic Digit Test, Competing Sentence Test, Phonemic Synthesis Test, and Staggered Spondaic Word Test, Pitch Pattern Sequence. They were also given the following SCAN-3 subtests: Filtered Words, Competing Sentence Test, Competing Words-Directed Ear, and Time-Compressed Sentences. Individualized screening and the diagnostic battery were utilized according to the patient's chief complaint and overall history. APD diagnosis was established based on the criteria recommended by the American Academy of Audiology (AAA) and the American Speech-Language-Hearing Association (ASHA).5,6 A total of 44 participants were diagnosed with APD. The relationships between and within questionnaire- and performance-based screening tools were measured using Spearman's correlation. The results from the screening tools were compared with the diagnostic test results and the APD diagnosis to determine the efficiency of the screeners.
A moderate relationship was observed among questionnaire-based screeners—BMQ-R and FAPC (r =.42), BMQ-R and CHAPS (r =.39), and FAPC and CHAPS (r =.54)—as they aim to investigate similar listening behaviors. This implies that individuals who performed poorly on one screener also did poorly on the other. The relationship between BMQ-R and FAPC and CHAPS was negative, indicating that a higher score on the BMQ-R was associated with a lower score on the FAPC and CHAPS, which demonstrates poor performance and vice versa. Since questionnaire-based tools evaluate subjective perceptions of an individual's overall auditory behaviors, they did not correlate with the process-specific performance-based screeners as well as the diagnostic tests.
On the other hand, no relationship was found among performance-based screeners, suggesting that an individual's performance on one screener was independent of the other since they assess different auditory processes. The performance-based screeners, specifically CW-FR, predicted the score on APD diagnostic tests with more accuracy than did the questionnaire-based screeners, with the Spearman's correlation r ranging from .34 to −.75. It also exhibited a high positive predictive value percentage (70%) for the diagnosis of APD. The performance-based screeners, when administered as a battery, predicted the diagnosis of APD more accurately than an individual screening test (χ2(1, N = 75) = 14.17, p <.01).
Effective screening procedures are beneficial since they allow more time for other services, reduction of costs, fewer over-referrals, and an increase in the efficiency of identification and intervention for APD. They promote early identification, which helps minimize the negative impact of APD in children. The results of the study revealed the importance and value of performance-based screening tools, specifically CW-FR and SCAN-3 battery, in the identification of individuals at risk of APD. Caution should be maintained when making a referral for an APD evaluation, which means only using questionnaire-based screeners. The behaviors listed in questionnaire-based screeners are not specific to APD and could be observed in other behavioral conditions related to language, learning, and attention. Furthermore, the questionnaires were limited due to the potential bias of the observers and the health literacy of the respondents. This study emphasizes the need to update the AAA and ASHA guidelines and establish an identification- and evaluation-specific protocol for APD.