Laboratoire Chelles surdité, Chelles, France.
PLoS One. 2012;7(12):e51915. doi: 10.1371/journal.pone.0051915. Epub 2012 Dec 20.
Over the last three years of hearing aid dispensing, it was observed that among 74 subjects fitted with a linear octave frequency transposition (LOFT) hearing aid, 60 reported partial or complete tinnitus suppression during day and night, an effect still lasting after several months or years of daily use. We report in more details on 38 subjects from whom we obtained quantified measures of tinnitus suppression through visual analog scaling and several additional psychoacoustic and audiometric measures. The long-term suppression seems independent of subject age, and of duration and subjective localization of tinnitus. A small but significant correlation was found with audiogram losses but not with high frequency loss slope. Long-term tinnitus suppression was observed for different etiologies, but with a low success rate for sudden deafness. It should be noted that a majority of subjects (23) had a history of noise exposure. Tinnitus suppression started after a few days of LOFT hearing aid use and reached a maximum after a few weeks of daily use. For nine subjects different amounts of frequency shifting were tried and found more or less successful for long-term tinnitus suppression, no correlation was found with tinnitus pitch. When the use of the LOFT hearing aid was stopped tinnitus reappeared within a day, and after re-using the LOFT aid it disappeared again within a day. For about one third of the 38 subjects a classical amplification or a non linear frequency compression aid was also tried, and no such tinnitus suppression was observed. Besides improvements in audiometric sensitivity to high frequencies and in speech discrimination scores, LOFT can be considered as a remarkable opportunity to suppress tinnitus over a long time scale. From a pathophysiological viewpoint these observations seem to fit with a possible re-attribution of activity to previously deprived cerebral areas corresponding to high frequency coding.
在过去三年的助听器验配过程中,观察到 74 名受试者使用线性倍频程转置(LOFT)助听器后,60 名受试者报告在白天和夜间部分或完全抑制了耳鸣,这种效果在数月或数年后的日常使用中仍然持续。我们更详细地报告了 38 名受试者的情况,我们通过视觉模拟评分以及其他一些心理声学和听力测量方法获得了量化的耳鸣抑制测量值。长期抑制似乎与受试者年龄、耳鸣的持续时间和主观定位无关。发现与听力图损失有较小但显著的相关性,但与高频损失斜率无关。不同病因的耳鸣均观察到长期抑制,但突发性耳聋的成功率较低。值得注意的是,大多数受试者(23 名)有噪声暴露史。LOFT 助听器使用几天后开始抑制耳鸣,使用数周后达到最大值。对 9 名受试者尝试了不同程度的频率转移,发现对长期耳鸣抑制或多或少有效,但与耳鸣音调无关。当 LOFT 助听器停止使用时,耳鸣在一天内重新出现,重新使用 LOFT 助听器后,耳鸣再次在一天内消失。对于 38 名受试者中的约三分之一,还尝试了经典放大或非线性频率压缩助听器,但没有观察到这种耳鸣抑制。除了高频听力敏感度和言语辨别评分的改善外,LOFT 还可以被视为在长时间范围内抑制耳鸣的显著机会。从病理生理学的角度来看,这些观察结果似乎与先前剥夺的与高频编码相对应的大脑区域的活动重新归因相符。