a Department of Otorhinolaryngology and Head and Neck Surgery , Leiden University Medical Center , Leiden , the Netherlands.
b Leiden Institute for Brain and Cognition, Leiden University , Leiden , the Netherlands.
Int J Audiol. 2019 Sep;58(9):553-564. doi: 10.1080/14992027.2019.1601270. Epub 2019 Apr 23.
This study aimed to evaluate a more energy-efficient dynamic current focussing (DCF) speech-processing strategy after long-term listening experience. In DCF, tripolar stimulation is used near the threshold and loudness is controlled by the compensation coefficient σ. A recent acute pilot study showed improved spectral-temporally modulated ripple test (SMRT) scores at low loudness levels, but battery life was reduced to 1.5-4 hours. Within-subject comparisons were made for the clinical versus. DCF strategy after 5 weeks of at-home usage. Speech intelligibility in noise, spectral ripple discrimination, temporal modulation detection, loudness growth, and subjective ratings were assessed. Twenty HiRes90K (Advanced Bionics, Valencia, USA) cochlear implant (CI) users. Average battery life was 9 hours with the newly implemented DCF compared to 13.4 hours with the clinical strategy. Compared with measurements made at the beginning of the study, SMRT-scores and speech intelligibility in noise were significantly improved with DCF. However, both measures suffered from unexpected learning effects over time. The improvement disappeared and speech intelligibility in noise declined significantly relative to the final control measurement with the clinical strategy. Most CI users can adapt to the DCF strategy in a take-home setting. Although DCF has the potential to improve performance on the SMRT test, learning effects complicate the interpretation of the current results.
本研究旨在评估长期聆听体验后更节能的动态电流聚焦（DCF）语音处理策略。在 DCF 中，使用近阈刺激，响度由补偿系数σ控制。最近的一项急性初步研究表明，在低响度水平下，频谱时变调制纹波测试（SMRT）的评分有所提高，但电池寿命缩短至 1.5-4 小时。在 5 周的家庭使用后，对临床策略与 DCF 策略进行了个体内比较。评估了噪声下言语可懂度、频谱纹波辨别、时间调制检测、响度增长和主观评价。20 名 HiRes90K（Advanced Bionics，美国瓦伦西亚）人工耳蜗植入（CI）使用者。与临床策略相比，新实施的 DCF 平均电池寿命为 9 小时，而临床策略为 13.4 小时。与研究开始时的测量值相比，SMRT 评分和噪声下言语可懂度随着 DCF 的使用而显著提高。然而，这两个指标都随着时间的推移出现了意想不到的学习效应。与临床策略的最终对照测量相比，SMRT 评分的提高消失，噪声下言语可懂度显著下降。大多数 CI 用户可以在家中环境中适应 DCF 策略。尽管 DCF 有可能提高 SMRT 测试的性能，但学习效应使当前结果的解释变得复杂。
