3.2The auditory perception outcomes
An improvement was observed in comparing Ling’s sound test scores with the first evaluation period postoperative scores (Table 2). There was a significant difference between preoperative and postoperative in all children with IP-I (F1-71 = 16.056, p -value < .005), cochlear hypoplasia (F1-51 = 18.769, p -value < .005) and common cavity(F1-15 = 76.164, p -value < .005). There were no preoperative and postoperative statistical differences compared to children with other IEMs.
The comparison of the preoperative MAIS scores and the one-six months and one-three years’ postoperative scores showed that auditory integration improved significantly (Table 3), and all children with IEMs benefitted from CI (Figure 1). Also, there were remarkable differences between the MAIS scores of the different malformation groups in three years after surgery. A comparison of the MAIS scores of children with common cavity showed statistical difference at all periods (F1-15 =10.186, p -value < .005), but their rate of development was so slow than children with IEMs and normal cochlea.Also, children with (IP-I F1-71 = 16.056, p -value < .005) and cochlear hypoplasia (F1-51= 18.769, p -value < .005) showed a significant difference between preoperative and postoperative in MAIS scores.
Table 4 and Figure 2 presented results of closed-set PPT and open-set SRT. All children with normal cochlea completed the closed-set and open-set tests in second evaluation period with relative success. However, children with IP-I, cochlear hypoplasia, common cavityand dilatation of vestibulehad not yet reached the open set SRT test within one-three years.Children with different IEMs also achieved very low scores, except EVA (F1-27 = .955, p -value = .337; F1-27 = 1.050, p -value = .315), IP-II (F1-79 = .071, p -value = .791; F1-79 = .062, p -value = .804) and IP-III (F1-19 = 1.991, p -value = .175; F1-19 = .188, p -value = .670)patients. A comparison of the PPT and SRT scores of children with IP-I (F1-71 = 25.262, p -value < .005; F1-71 = 47.216, p -value < .005), cochlear hypoplasia (F1-51 = 33.196, p -value < .005; F1-51 = 31.908, p -value < .005)common cavity(F1-15=33.286, p -value < .005; F1-15=30.621, p -value < .005) and dilatation of vestibule (F1-5 = 11.172, p -value < .005; F1-5 = 16.000, p -value < .005)showed statistical difference.
Enlarged vestibular aqueduct obtained the first group of children with the highest scores in terms of auditory perception performance among IEMs. The children with EVA achieved open set SRT approximately 80%. Unfortunately, children with common cavity constituted the lowest score group for auditory perception results. In the Ling’s Sound Test and MAIS evaluation performed before the CI, in common cavity had the lowest scores compared within the normal cochlea, and statistically significant differences were found (p -value < .005). In the MAIS test, between second evaluation periods after CI, in common cavity had a score of 25.38 points while in normal cochlea had a score of 40 full points. Although they could only complete the closed-set PPT, they were unable to open-set SRT.