Comparism Of Loudness Growth Functions Between Children With Normal Hearing And Children With Sensorineural Hearing Loss By The Modified Contour Test

Objective To compare the loundness growth of normal hearing children and children with sensorineural hearing loss(SNHL) by the modified contour test. To collect the normative data of loudness growth function in children and to apply the results to individual hearing aids fitting. Methods The loudness growth function were obtained in 20 ears with normal hearing and 17 ears with SNHL using the modified contour test. 2 or 3 weeks later after the initial test, 3 ears with normal hearing and 2 ears with SNHL that were randomly selected were retested. The test results were analyzed by the Univariate Analysis of Variance .Results There was significant difference between the loudness growth of normal hearing group and groups with SNHL of different degrees (p<0.005), and also between different loundness categories(p<0.003). There was significant difference (p<0.004) between 1kHz and other 4 frequencies(0.5kHz, 2k-4kHz). No significant difference (p>0.998) was found among the 4 frequencies (0.5k/2k/3k/4k). The test-retest reliability of loudness growth function obtained in normal hearing and hearing-impairedgroup was highly correlated. The results of modified contour test showed good reliability.Conclusion Loudness growth in children with SNHL is different that in normal hearing children. The following results were found in the loundness growth in children with SNHL: the more serious the hearing loss is, the more rapid the loundness growth and the smaller the dynamic range. The advantages of the modified contour test are: it is a vivid and easy-to-do test for children, also a quick test with good reliability. In order to fit hearing aids properly for children, it is worth applying the modified contour test in clinic.