Maturation of speech-in-noise performance in children using binaural diotic and antiphasic digits-in-noise testing

Abstract

Digits-in-noise (DIN) tests have become very popular over the past 15 years for hearing loss detection. Several recent studies have highlighted the potential utility of digits-in-noise (DIN) as a school-aged hearing test. However, age may influence test performance in children. In addition, a new antiphasic stimulus paradigm has been introduced. This study determined the maturation of speech recognition for diotic and antiphasic DIN in children and evaluated DIN self-testing in young children. A cross-sectional, quantitative, quasi-experimental research design was used in this study. Participants with confirmed normal hearing were tested with diotic and antiphasic DIN test. During the DIN test, arrangements of three spoken digits were presented in noise via headphones at varying signal-to-noise ratios (SNRs). The researcher entered each three-digit sequence the participant said on a smartphone keypad. Six hundred and twenty-one normal hearing (bilateral pure tone threshold of ≤ 20 dB HL at 1, 2, and 4kHz) children between the ages of 6-13 years with normal hearing were recruited in order to examine the comparative maturation of diotic and antiphasic performance. A further sample of 30 first grade (7-year-old) children with normal hearing were recruited to determine the validity of self-testing on a smartphone. Multiple regression analysis including age, gender, and English additional language (i.e. Person whose first language or home language is not English) showed only age to be a significant predictor for both diotic and antiphasic SRT (p < 0.05). Speech reception thresholds improved by 0.15 dB and 0.35 dB SNR per year for diotic and antiphasic SRT, respectively. Post hoc multiple age group comparisons using Bonferroni adjustment for multiple comparisons (by year) showed SRTs for young children (6 to 9 years old) differed significantly from older children (11 to 13 years old) (p < 0.05). There was no significant difference in SRT between age 10 and upward. Self- and facilitated testing in young children was significantly (p > 0.05) different for the antiphasic condition and demonstrated poor reliability in diotic and antiphasic conditions. Increasing age was significantly associated with improved SRT using diotic and antiphasic DIN. Beyond 10 years of age, SRT results of children became more adult-like. However, age effects were only significant up to 10 and 12 years for antiphasic and diotic SRT, respectively. Furthermore, between self- and facilitated testing, the SRT difference was not significant (p > 0.05).