Assessment of Functional Hearing in Greek-Speaking Children Diagnosed with Central Auditory Processing Disorder

Including speech recognition in noise testing in audiological evaluations may reveal functional hearing deficits that may otherwise remain undetected.

The current study explored the potential utility of the Speech-in-Babble (SinB) test in the assessment of central auditory processing disorder (CAPD) in young children for whom diagnosis is challenging.

A cross-sectional analysis.

Forty-one Greek children 4-13 yr of age diagnosed with CAPD and exhibiting listening and academic problems (clinical group) and 20 age-matched controls with no listening or academic problems participated in the study.

All participants' auditory processing was assessed using the same tests and instrumentation in a sound-treated room. Two equivalent lists of the SinB test, developed at the Psychoacoustic Laboratory of the Aristotle University of Thessaloniki, were administered monaurally in a counterbalanced order. SinB consists of lists of 50 phonetically balanced disyllabic words presented in background multitalker babble. Five signal-to-noise ratios (SNRs) were used in a fixed order. The children were instructed to repeat the word after each presentation. The SNR at which the child achieved 50% correct word identification served as the dependent variable or outcome measure, with higher SinB scores (measured in SNR dB) corresponding to poorer performance.

SinB performance was better (lower SNR) for the normal control group versus the clinical group [F(1,35) = 43.03, p < 0.0001]. SinB inversely correlated with age for both CAPD and control groups (r = -0.648, p << 0.001 and r = -0.658, p < 0.005, respectively). Regression analysis revealed that linear models better explained the variance in the data than a quadratic model for both the control and CAPD groups. The slope (beta value of the linear model) was steeper for the clinical group compared to the control group (beta = -0.306 versus beta = -0.130, respectively). An analysis of covariance run with age as the covariate to assess the potential effect of comorbidity on SinB performance in children with CAPD with and without comorbid conditions revealed no significant differences between groups [F(1,38) = 0.149, p > 0.05].

This study offers the first detailed presentation of the performance of Greek children on a Greek language SinB test. The main finding is that SinB scores improved as a function of age in a constant manner as represented by the slope of the linear regression line for both CAPD and control groups. Results suggest that this speech recognition in competition test holds promise for differentiating typically developing Greek children from those children with CAPD across the age range studied here (4-13 yr). The SinB seemed rather immune to the presence of comorbid conditions presented by some of the children in this study, suggesting its potential utility as a valid measure of central auditory processing. While there are many speech-in-noise or competition tests in English, there are fewer in other languages. Tests like the SinB should be developed in other languages to ensure that children demonstrating "listening" problems can be properly evaluated.