Effect of middle ear effusion on distortion product otoacoustic emissions

ABSTRACT

Otitis media with effusion is a very common childhood disease which has negative effects on the feasibility of recording of otoacoustic emissions. The aim of the present study was to determine the influence of different types of effusion on distortion product otoacoustic emissions [DPOAE]. Preoperative and first postoperative day DPOAE signal to noise ratio were compared in 50 children [100 ears] undergoing myringotomy and/ or tympanostomy tube insertion for secretary otitis media. The results were analyzed by paired samples test and ANOVA. In the preoperative evaluation, glue effusion caused a significant reduction in DPOAE at 2, 4 and 8 kHz [p<0.05] compared to serous or mucous effusion. Comparison between preoperative and first postoperative day DPOAE signal to noise ratios showed significant differences at 1, 1.5, 2 and 4 kHz [p< 0.05]. On the first postoperative day, the maximum increase in emission was observed at 2 kHz in ears which previously showed glue effusion. Glue effusion causes a reduction in DPOAEs at 2, 4 and 8 kHz more than other types of effusion