Study of the neural plasticity in adults and older adults new hearing aid users

ABSTRACT Purpose: to monitor, with long-latency auditory evoked potentials, the plasticity of the central auditory pathways in adults and older adults, new users of hearing aids. Methods: a total of 15 adults and older adults, aged 55 to 85 years, participated in the research. They had a symmetric bilateral mild to moderate sensorineural hearing loss, without previous experience with any type of hearing aid. The long-latency auditory evoked potentials were conducted with and without amplification, at 60 and 75 dBnHL, with speech stimulus in a sound field, in two assessment moments: up to one week after fitting the hearing aid and after six months of its use. The Student’s t-test was used for statistical analysis, considering significant the p-value < 0.05. Results: responses with lower latency values were observed for the right ear in the second assessment. Comparing the first with the second assessment, both with and without the hearing aid, an increase in the amplitude of P2-N2 was observed, as well as an increase in the latency of the P2 component at the intensity of 75 dBnHL. No statistically significant differences were observed at the intensity of 60 dBnHL. Conclusion:the use of the hearing aid promoted the plasticity of the central auditory pathways, increasing the number of neurons responsive to the sound stimuli.

摘要
目的：采用长潜伏期听觉诱发电位（long-latency auditory evoked potentials），监测成人及老年助听器新使用者的中枢听觉通路可塑性。
方法：本研究共纳入15名年龄介于55至85岁的成人及老年受试者，均存在对称性双侧轻中度感音神经性听力损失，且既往未使用过任何类型助听器。分别于两个评估时间点开展检测：助听器适配后1周内，以及使用助听器6个月后。检测在声场环境中以言语声作为刺激信号，分别在60 dBnHL与75 dBnHL声强下，记录受试者佩戴助听器与未佩戴助听器状态下的长潜伏期听觉诱发电位。统计学分析采用学生t检验（Student’s t-test），以p值<0.05作为差异具有统计学意义的判定标准。
结果：第二次评估中，右侧耳的诱发电位潜伏期更短。对比两次评估结果，无论是否佩戴助听器，在75 dBnHL声强下均观察到P2-N2波幅升高，且P2成分潜伏期延长；而在60 dBnHL声强下未观察到统计学显著差异。
结论：佩戴助听器可促进中枢听觉通路可塑性，增加对声刺激产生响应的神经元数量。