Auditory Recognition of Words and Digits in Multitalker Babble in Learning-Disabled Children with Dichotic Listening Deficit

Background: Previous studies have reported the weakness of recognition of speech-in-noise and dichotic listening deficit in Learning-Disabled (LD) children. This study aimed at further investigating these two deficits in LD children. Methods: Overall, 33 LD children with dichotic listening deficit from a government rehabilitation center and 39 normal-achieving (NLA) children from three elementary schools were selected with the convenience sampling method to participate in this cross-sectional study (Tehran, Iran). Learning-disabled children were categorized in two categories of unilateral dichotic separation deficit (UDSD) and bilateral dichotic separation deficit (BDSD). Results: Mean (± SD) of signal-to-noise ratio (SNR) for binaural recognition of words and digits-in-noise in LD children (3.5 ± 1.7 and -11.0 ± 2.1 dB, respectively) was significantly higher than corresponding means of NLA children (1.8 ± 1.1 and -13.8 ± 1.1 dB, respectively (P = 0.001)). Mean SNR of the right ear in BDSD children in recognition of words-in-noise (5.0 ± 1.9 dB) was significantly higher than that of the right ear in UDSD children (3.5 ± 1.5 dB; P = 0.018, d = 0.96). Conclusions: Monaural and binaural recognition of words and digits-in-noise are impaired in LD children with dichotic listening deficit. It seems that BDSD children show an inter-aural asymmetry in recognition of words-in-noise with poorer performance in the right ear.