The effects of chronic otitis media with effusion on the measurement of distortion products of otoacoustic emissions: presurgical and postsurgical examination.

This study aims to determine the influence of middle ear effusion and inserted tympanostomy tubes on the feasibility of recording and of the amplitude of distortion product otoacoustic emissions (DPOAE). Effusion in the middle ear reduces the number of measurable responses and their amplitude in the whole range of frequencies from 0.5 to 8 kHz. These changes were more distinct in mucous than in serous effusion. There was an increase in the number of measurable responses and amplitude of DPOAE after surgery. Inserted tympanostomy tubes have no influence on the feasibility of DPOAE recording but reduce their amplitude in comparison to the control group.

[Functional hearing loss in children]. / Czynnosciowe zaburzenia sluchu u dzieci.

The cases of children diagnosed with pseudohypacusis in the Department of Pediatric Otolaryngology were presented. Probable mechanism of its pathogenesis was described. The main stress was put on its correct diagnosis particularly in children with co-existing organic changes. Diagnosis of pseudohypacusis in children is not problematic provided that the occurence of this disease is taken into consideration during diagnostic procedures.

[The influence of the middle ear status on the measurement of evoked otoacoustic emissions (DPOAE)]. / Wplyw stanu ucha srodkowego na wywolane emisje otoakustyczne (DPOAE).

The aim of this study was to evaluate the influence of the middle ear status on detection and amplitude of otoacoustic emissions-DPOAE. DPOAE were detected in all healthy ears and their amplitude was between 11.4 and 22.4 dB SPL. Responses at frequencies of 0.5 and 0.75 kHz were not detected in the group of children with Eustachian tube dysfunction in 60% and 27% of ears respectively. The absence of DPOAE responses in the group of children with B type tympanometry was found in 3/4 of the investigated ears at frequencies of 0.5 and 0.75 kHz and in over 50% of ears at frequencies of 1.0 and 8.0 kHz. No influence of cochlear reserve on detection and amplitude of DPOAE was found in the studied group. Conductive hearing loss associated with a presence of negative pressure and effusion in the middle ear inhibits DPOAE detection and causes decrease of otoacoustic emission amplitude.