The effects of alterations in the osseous external auditory canal on perceived sound quality

Objective of this work was to evaluate the perceptual effect of the acoustic properties before and after canalplasty and a reconstruction of the posterior canal wall in revision modified radical cavity surgery. This is a prospective study. Twenty normal hearing subjects were presented six simulated sound conditions representing the acoustic properties of six different ear canals (two normal ears, and two pre- and postoperative conditions). The six different real ear unaided responses of these ear canals were used to filter Dutch sentences, resulting in six simulated sound conditions. A seventh unfiltered ‘reference’ condition was used for comparison. Sound quality was evaluated using a seven-point paired comparison rating and a visual analogue scale (VAS). Significant differences in sound quality were found between all conditions and the pre-operative cavity condition (all p < 0.001) using both the paired comparison rating and VAS. No significant differences in VAS were found comparing the other conditions with each other. But when using the paired comparison rating, the post-operative canalplasty condition and both the pre and post-operative cavity conditions differed significantly from the other conditions. This explorative study shows that altering the acoustics of the OEAC after a canalplasty and a reconstruction of the ear canal in revision modified radical cavity surgery results in perceivable changes in sound quality. It is likely that these changes are primarily due to volume changes. To which extent these changes are of clinical importance remains to be determined.Electronic supplementary materialThe online version of this article (doi:10.1007/s00405-016-3910-z) contains supplementary material, which is available to authorized users.

Section: Participants and Methodsmentioning

confidence: 99%

Section: Participants and Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The effects of a canalplasty and a canal wall reconstruction on perceived sound quality: preliminary results

Spronsen

Brienesse

Ebbens

et al. 2016

“…Due to its anatomical dimensions the external auditory ear canal acts as a filter to reduce low frequencies and enhance mid to high frequencies [3]. Surgical modification of the osseous external auditory canal (OEAC) changes the acoustic properties of the external ear canal [4][5][6][7][8][9]. For example, in case of a cavity condition, the acoustic properties shift towards an amplification of the soundwaves of low to mid frequencies and an reduction in soundwaves of high frequencies [8].…”

Section: Introductionmentioning

confidence: 99%

“…Surgical modification of the osseous external auditory canal (OEAC) changes the acoustic properties of the external ear canal [4][5][6][7][8][9]. For example, in case of a cavity condition, the acoustic properties shift towards an amplification of the soundwaves of low to mid frequencies and an reduction in soundwaves of high frequencies [8]. In case of revision, radical cavity surgery with reconstruction of the posterior wall of the cavity near-normal acoustic characteristics were measured [9].…”

Section: Introductionmentioning

confidence: 99%

Can we predict the altered subjective quality assessment of sound after ear canal surgery?

Zwemstra

Brienesse

Ebbens

et al. 2020

Purpose To correlate the subjective quality assessment of ear canal acoustics of the participants to the objective measurement of the ear canal acoustics. The objective ear canal acoustics is the frequency-dependent modulation of soundwaves through the ear canal. Our second objective is to design a model to predict the subjective quality of sound based on the altered objective ear canal acoustics. Methods To determine the frequency-dependent modulation of the soundwaves the real-ear unaided gain (REUG) of the ear canal is measured. 40 participants with normal hearing were presented six simulated sound fragments representing the acoustic properties of six different ear canals (REUG). These six sound fragments were built based on the difference between these six REUGs and the average REUG of a normal adult ear canal. Subjective sound quality was evaluated using a VAS score and a paired comparison score. Results We found a strong correlation between the objective ear canal acoustics and the subjective assessment of the quality of sound (Spearman's rho-0.89). Our linear mixed VAS model for individual participants has an intercept of 95.6 and a slope of − 4.2 (p < 0.001). The paired comparison analysis endorsed our findings that an increased difference in REUG is predictive for a decreased quality assessment of ear canal acoustics. Conclusion There is a strong correlation between the subjective evaluation of ear canal acoustics and the objective quality assessment of ear canal acoustics. Our models show that an increased difference in REUG predicts a decreased quality of ear canal acoustics.

Hearing and hearing rehabilitation after obliteration of troublesome mastoid cavities

Geerse

Bost

Allagul

et al. 2020

Self Cite

Purpose The purpose of this study is the evaluation of post-operative hearing threshold after revision surgery and obliteration of troublesome canal wall down mastoidectomy cavities (CWDMCs). The ability to use and tolerate conventional hearing aids (CHAs) was also evaluated. Methods A retrospective chart analysis of 249 patients with chronically draining CWDMCs who underwent revision surgery including obliteration of the mastoid cavity between 2007 and 2017 at the AMC location of the Amsterdam University Medical Centers (Amsterdam UMC) was performed. Patient characteristics, pre- and post-operative Merchant grade, surgical outcomes, pre- and post-operative hearing thresholds, and the ability/necessity to use a CHA or the ability/necessity to use a Bone Conduction Device (BCD) were recorded. Results Dry ears were found in 95% of the total cohort. Residual disease was detected in 1.6% during MRI follow-up with no residual cholesteatoma in the obliterated area. In 3.2% of the patients, recurrent disease was found. A significant improvement in mean air conduction level, mean bone conduction level, and mean air-bone gap (ABG) was found post-operatively (p < 0.05). For all types of ossicular chain reconstruction, a significant improvement in mean Pure Tone Average was observed (p < 0.05). The percentage of patients with an indication for CHA was similar pre- and post-operatively (67% both pre- and post-operatively). The ability to use a CHA improved from 3% pre-operatively to 57% post-operatively (p < 0.001). Conclusion This study shows that revision surgery and obliteration of CWDMCs enable successful CHA rehabilitation post-operatively. Upon this type of surgery, hearing thresholds improve significantly, but the need for rehabilitation with a CHA remains necessary in most cases.