Slight-mild sensorineural hearing loss in children: audiometric, clinical, and risk factor profiles

Slight or mild hearing loss has been posited as a factor affecting speech, language, learning, and academic outcomes, but the risk factors for slight-mild sensorineural hearing loss (SNHL) have not been ascertained. The two specific aims for this research were (1) to describe the audiometric and clinical characteristics of children identified with slight-mild bilateral SNHL and (2) to compare children with slight-mild SNHL with those with normal hearing (NH) with respect to potential risk factors for congenital or acquired for hearing loss.

A cross-sectional cluster sample survey of 6581 children enrolled in years 1 and 5 of Australian elementary school was completed. Children were screened for slight-mild SNHL, defined as a low- and/or high-frequency pure-tone average of 16 to 40 dB HL in the better ear, with air-bone gaps <10 dB. Children who did not pass the screen received air and bone conduction threshold and tympanometry tests to determine the type and degree of hearing loss. The parents of every child who participated in this study completed a questionnaire, before the hearing screening, to ascertain possible risk indicators. The questionnaire included items regarding the family's demographics, hearing status of family members, the presence of risk factors, and parental concern regarding the child's hearing.

Fifty-five children with slight-mild SNHL and 5490 with NH were identified. Of the group with SNHL, 39 children had a slight loss (16 to 25 dB HL) and 16 had a mild loss (26 to 40 dB HL). The majority of the losses were bilateral and symmetrical, and the mean pure-tone average for the better ear for all 55 children was 22.4 dB HL (SD, 5.2). The most prevalent risk factor was "neonatal intensive care unit/special care nursery admission," which was reported for 12.5% of the SNHL and 8.4% of the NH group. Reported use of personal stereos was a significant risk factor with an odds ratio of 1.7 (95% confidence interval = 1.0 to 3.0, p = 0.05). The questions relating to parental concern for their child's hearing had low sensitivity (<30%) and very low positive predictive values (<3%) for detecting slight-mild SNHL.

Slight-mild SNHL had a prevalence of 0.88% among the school-aged population sampled, with the majority of these children exhibiting bilateral, symmetrical audiometric configurations. Conventional risk factors for hearing loss were not strongly predictive of slight-mild SNHL nor were parental concerns about the child's hearing ability. The association between slight-mild SNHL and the parent report of personal stereo use suggests that this type of noise exposure may be a risk factor for acquired hearing loss. This seems to be the first documentation of such an association in a large sample of young children.