Materials and Method: We included a total of 20 patients aged 56 to 86 years who had symmetric bilateral sensorineural hearing loss increasing towards higher frequencies due to presbyacusis.
Results: Free field measurements performed with new and old standard ear mold tubes revealed statistically significant improvements in hearing thresholds at 2000 Hz and 4000 Hz, and discrimination scores. In probe tube microphone measurements, statistically significant gains were determined at 1600, 2000, 2500, 4000 and 6000 Hz. Correlations were found between duration of use of ear mold tubes and both the increases at 2000 Hz and 4000 Hz in free field measurements with hearing aids with old and new tubes and the increases above 2000 Hz in probe microphone measurements.
Conclusion: Ear mold tube deformation in digital behind the ear hearing aids appears to cause loss of advantage which is more pronounced in higher frequencies. To avoid loss of amplification caused by deformation of ear mold tubes in patients using hearing aids who have sensorineural hearing loss in high frequencies as in presbyacusis, ear mold tubes should be carefully fitted and polyvinyl chloride ear mold tubes known to be easily affected by external physical factors such as temperature and ultraviolet light should be controlled periodically and renewed if necessary.
Keywords : Hearing Loss, Sensorineural; Hearing Aids; Eustachian Tube