Audiologic assessment of extremely low birth weight infants: a preliminary report.

Abstract

The aim of this study was to assess all relevant aspects of auditory function, including acuity and perception, of a cohort of extremely low birth weight (< 1000 g) children who survived to 8 years of age; 42 of the 59 consecutive survivors born over a 4-year period from January 1, 1977, had a full auditory assessment. Of the 42 children, 4 (9.5%) had a sensorineural hearing impairment, 5 (11.9%) had a conductive hearing impairment, 24 (57.1%) had figure/ground differentiation problems, and 20 (47.6%) had a short-term auditory memory problem. The 4 children with sensorineural hearing impairments had had significantly higher maximum concentrations of bilirubin in the newborn period (median 167 mumol/L vs 138 mumol/L and had required more intensive care; at 8 years of age they were significantly disadvantaged in verbal ability. The 5 children with conductive hearing impairments were not significantly different on any perinatal or other 8-year outcome variables. The proportion with figure/ground differentiation problems (57.1%) was significantly higher than in a normative population (11.7%, chi 2 = 24.2). Extremely low birth weight children with figure/ground differentiation problems were more likely to be restless in the classroom (45.0% [9/20]) than those without these problems (16.7% [2/12]), but the difference was not statistically significant (chi 2 = 2.7). Children with short-term auditory memory problems had significantly higher maximum bilirubin concentrations in the newborn period (median 152 mumol/L vs 137.5 mumol/L). At 8 years of age they had significantly reduced intelligence and reading ability.(ABSTRACT TRUNCATED AT 250 WORDS)