RESUMO
Background: This study assessed the relationship between working memory capacity and auditory stream segregation by using the concurrent minimum audible angle in children with a diagnosed auditory processing disorder [APD]
Methods: The participants in this cross-sectional, comparative study were 20 typically developing children and 15 children with a diagnosed APD [age, 9-11 years] according to the subtests of multiple-processing auditory assessment. Auditory stream segregation was investigated using the concurrent minimum audible angle. Working memory capacity was evaluated using the non-word repetition and forward and backward digit span tasks. Nonparametric statistics were utilized to compare the between-group differences. The Pearson correlation was employed to measure the degree of association between working memory capacity and the localization tests between the 2 groups
Results: The group with APD had significantly lower scores than did the typically developing subjects in auditory stream segregation and working memory capacity. There were significant negative correlations between working memory capacity and the concurrent minimum audible angle in the most frontal reference location [0[degree sign] azimuth] and lower negative correlations in the most lateral reference location [60[degree sign] azimuth] in the children with APD
Conclusion: The study revealed a relationship between working memory capacity and auditory stream segregation in children with APD. The research suggests that lower working memory capacity in children with APD may be the possible cause of the inability to segregate and group incoming information
RESUMO
Comparing analog and digital hearing aids reducing disability caused by hearing deficiency among moderate to severe sensorineural hearing-impaired persons. This descriptive-analytic study was carried out on two groups of subjects participated in this study in some audiology clinics of hearing aid since May 2002 to October 2003. Twenty subjects wore analog hearing aids and twenty one subjects wore digital hearing aids. In this study , no subject had previous middle ear or psychological problems. APHAB questionnaire was completed before using hearing aid and 2 months after to determine benefit of hearing aid use. Total score mean of APHAB inventory before and after use of analoge hearing aids were 52.215 +/- 6.420 and 32.300 +/- 3.443 respectively. Also total score mean of APHAB inventory before and after use of digital hearing aids were 54.9252 +/- 9.028 and 26.321 +/- 10.916 respectively. There was no significant difference between total mean score of APHAB inventory before and after using analog and digital hearing aids [P=0.058].While there was significant difference between total mean score of APHAB questionnaire before and after use of analog hearing aids [P<0.001] and also before and after use of digital hearing aids [P<0.001]. Moreover age, gender , litracy level , occupation , degree of hearing loss and manner of hearing aid usage did not have significant effect on APHAB results. Configuration of loss had siginficant effect on aversiveness subscale before and after use of analog hearing aids [P =0.008]. Previous experience and duration of hearing aid usage had significant effect on aversiveness subscale before and after use of digital hearing aids [P=0.043] and [P=0.024], respectively , while all of these three items did not have significant effect on total mean score of APHAB inventory and also total mean scores of three subscales of ease of communication , reverberation and background noise. Comparing to analog hearing aid , digital one is significantly beneficial for reverberation and background noise for hearing-impaired persons , but it has no benefit for ease of communication and aversiveness that may be arised from effects of the individual expectation , psychological and personal factors