RESUMO
It is well documented that Otitis media with effusion [OME] is a very common childhood disease which precludes otoacoustic emissions [OAEs] recording. Trials of medical treatment may fail to resolve effusion and tympanostomy tubes may be recommended. The aim of the present study was to determine the prevalence of transient-evoked otoacoustic emissions [TEOAEs] in ears with patent tympanostomy tubes from children with normal hearing sensitivity. TEOAEs were measured in 64 children [128 ears] with normal hearing and patent tympanostomy tubes 4-8 weeks after surgery. Shepard grommet-type tube was inserted in 104 ears and T-type tube was inserted in 24 ears. Results indicate that passing TEOAEs was present in 123 ears [96%]. Of the 5 ears [4%] in which TEOAEs failed to be recorded, 1 ear has a Shepard grommet-type tube and the remaining 4 ears have T-type tubes. Analysis of TEOAEs by frequency bands demonstrated that in ears with grommet-type tubes and passed emissions [103 ears], TEOAEs was absent at 5 KHz band only in 24 ears [23%] and absent at 4 and 5 KHz bands only in 30 ears[29%]. While in ears with T-type tubes and passed emissions[20 ears], TEOAEs was absent at 5 KHz band only in 11 ears [55%] and absent at 4 and 5 KHz bands only in 16 ears[80%]. The use of T-type tube appeared to decrease the probability of obtaining normal TEOAEs in ears with normal peripheral hearing. However, the use of grommet-type tube had a negligible effect on recording TEOAEs, In conclusion, TEOAEs can be reliably used to test the function in the presence of tympanostomy tubes at least in frequency bands 1,2 and 3 KHZ and it is not necessary to wait until of the tubes