Effect of suppression of otoacoustic emissions in individuals with and without central auditory processing disorder: a systematic review

Objective

To investigate, through a systematic review of the literature, whether there are differences in the results of otoacoustic emissions suppression tests in individuals with and without central auditory processing disorder.

Methods

Searches were carried out in the scientific databases Latin American and Caribbean Health Sciences Literature, PubMed, Scientific Electronic Library Online, Web of Science, Scopus, Science Direct and Cochrane, as well as the databases of gray literature British Library, OpenGrey.eu and Object View and Interaction Design. A systematic review of the literature was carried out, with the descriptors otoacoustic emissions and auditory perceptual disorders and their synonyms, combined by the Boolean operators AND and OR. The reading of the studies was done by peers independently and in case of disagreement in the inclusion of studies, a third researcher was consulted. Original cross-sectional articles with a comparison group that suppressed transient evoked otoacoustic emissions in individuals with and without central auditory processing disorder were included.

Results

Seven studies that evaluated children aged between 7 and 14 years old were included, with methodological variability in the performance and analysis of the exam, the contralateral noise was the most used to elicit suppression. In only three studies did the group with central auditory processing disorder show lower suppression values, however the meta-analysis shows significant differences between the groups, with lower suppression values in the study groups.

Conclusion

This study points the need for a protocol that standardizes the measurement of OAE suppression and its findings, aiming to reduce the inclusion of results unrelated to the olivocochlear system.