Reis Luis Roque, Fernandes Paulo, Escada Pedro
Department of Otolaryngology of Egas Moniz Hospital, Centro Hospitalar de Lisboa Ocidental (CHLO), NOVA Medical School - Faculdade de Ciências Médicas, Lisbon, Portugal.
Department of Otolaryngology of Egas Moniz Hospital, Centro Hospitalar de Lisboa Ocidental (CHLO), NOVA Medical School - Faculdade de Ciências Médicas, Lisbon, Portugal.
Acta Otorrinolaringol Esp (Engl Ed). 2017 Jul-Aug;68(4):197-203. doi: 10.1016/j.otorri.2016.11.011. Epub 2017 Feb 10.
Bedside testing with tuning forks may decrease turnaround time and improve decision making for a quick qualitative assessment of hearing loss. The purpose of this study was to quantify the effects of ear canal occlusion on hearing, in order to decide which tuning fork frequency is more appropriate to use for quantifying hearing loss with the Contralateral Occlusion Test.
Twenty normal-hearing adults (forty ears) underwent sound field pure tone audiometry with and without ear canal occlusion. Each ear was tested with the standard frequencies. The contralateral ear was suppressed with by masking. Ear occlusion was performed by two examiners.
Participants aged between 21 and 30 years (25.6±3.03 years) showed an increase in hearing thresholds with increasing frequencies from 19.94dB (250Hz) to 39.25dB (2000Hz). The threshold difference between occluded and unoccluded conditions was statistically significant and increased from 10.69dB (250Hz) to 32.12dB (2000Hz). There were no statistically significant differences according to gender or between the examiners.
The occlusion effect increased the hearing thresholds and became more evident with higher frequencies. The occlusion method as performed demonstrated reproducibility. In the Contralateral Occlusion Test, 256Hz or 512Hz tuning forks should be used for diagnosis of mild hearing loss, and a 2048Hz tuning fork should be used for moderate hearing loss.
使用音叉进行床边测试可缩短周转时间，并改善对听力损失进行快速定性评估的决策。本研究的目的是量化耳道闭塞对听力的影响，以便确定在对侧闭塞试验中使用哪个音叉频率来量化听力损失更为合适。
20名听力正常的成年人（40只耳朵）在耳道闭塞和未闭塞的情况下接受声场纯音听力测定。每只耳朵都用标准频率进行测试。对侧耳朵通过掩蔽进行抑制。耳道闭塞由两名检查者进行。
年龄在21至30岁之间（25.6±3.03岁）的参与者，随着频率从19.94dB（250Hz）增加到39.25dB（2000Hz），听力阈值升高。闭塞和未闭塞条件下的阈值差异具有统计学意义，且从10.69dB（250Hz）增加到32.12dB（2000Hz）。根据性别或检查者之间没有统计学上的显著差异。
闭塞效应提高了听力阈值，且在较高频率时更为明显。所采用的闭塞方法具有可重复性。在对侧闭塞试验中，应使用256Hz或512Hz音叉诊断轻度听力损失，使用2048Hz音叉诊断中度听力损失。
