Reis Luís Roque, Castelhano Luís, Correia Filipe, Escada Pedro
Departamento de Otorrinolaringologia, Hospital Egas Moniz, Centro Hospitalar de Lisboa Ocidental - CHLO, NOVA Medical School, Faculdade de Ciências Médicas - Lisboa, Portugal.
Codas. 2019;31(3):e20180058. doi: 10.1590/2317-1782/20192018058. Epub 2019 Apr 18.
This study aimed to evaluate the effects of complete external ear canal occlusion on hearing thresholds with aging. The goal was to decide which tuning fork is more appropriate to use for the contralateral occlusion test (COT), in individuals of different ages.
Forty-two normal hearing subjects between 21 and 67 years were divided into three age groups (20-30 years, 40-50 years, and 60-70 years). Participants underwent sound field audiometry tests with warble tones, with and without ear canal occlusion. Each ear was tested with the standard frequencies (250, 500, 1000, and 2000 Hz). The contralateral ear was suppressed by masking.
Hearing thresholds showed an increase as the frequency increased from 20.85 dB (250 Hz, 20-30 years group) to 48 dB (2000 Hz, 60-70 years group). The threshold differences between occlusion and no occlusion conditions were statistically significant and increased ranging from 11.1 dB (250 Hz, 20-30 years group) to 32 dB (2000 Hz, 20-30 years group). We found statistically significant differences for the three age groups and for all evaluations except to 500 Hz difference and average difference. The mean hearing loss produced by occlusion at 500 Hz was approximately 19 dB. We found no statistically significant differences between right and left ears and gender for all measurements.
We conclude that the use of the 512 Hz tuning fork is the most suitable for COT, and its use may allow clinicians to distinguish mild from moderate unilateral conductive hearing loss.
本研究旨在评估外耳道完全闭塞对听力阈值随年龄变化的影响。目标是确定在不同年龄段的个体中，哪种音叉更适合用于对侧闭塞试验（COT）。
将42名年龄在21至67岁之间的听力正常受试者分为三个年龄组（20 - 30岁、40 - 50岁和60 - 70岁）。参与者接受了有和没有外耳道闭塞情况下的啭音声场听力测试。每只耳朵都用标准频率（250、500、1000和2000赫兹）进行测试。对侧耳朵通过掩蔽进行抑制。
随着频率从20.85分贝（250赫兹，20 - 30岁组）增加到48分贝（2000赫兹，60 - 70岁组），听力阈值升高。闭塞和非闭塞条件下的阈值差异具有统计学意义，范围从11.1分贝（250赫兹，20 - 30岁组）增加到32分贝（2000赫兹，20 - 30岁组）。我们发现三个年龄组以及除500赫兹差异和平均差异外的所有评估均存在统计学显著差异。500赫兹时闭塞产生的平均听力损失约为19分贝。所有测量中，我们未发现左右耳及性别之间存在统计学显著差异。
我们得出结论，512赫兹音叉最适合用于COT，使用它可能使临床医生能够区分轻度与中度单侧传导性听力损失。
