Voice parameters in children with cochlear implants: a systematic review and meta-analysis

ABSTRACT: Introduction: An intact auditory system is essential for the development and maintenance of voice quality and speech prosody. On the contrary hearing loss affects the adjustments and appropriate use of organs involved in speech and voice production. Spectro-acoustic voice parameters have been valuated in CI users, and the authors of previous systematic reviews on the topic concluded that preliminary Fundamental Frequency seemed the most reliable parameter to evaluate voice alterations in adult CI users. The main aim of this systematic review and meta-analysis was to clarify the vocal parameters and prosodic alterations of speech in pediatric CI users. Materials and methods: The protocol of the systematic review was registered on the PROSPERO database International prospective register of systematic reviews. We conducted a search of the English literature published in the period between January 1st 2005 and April 1st 2022 on the Pubmed and Scopus databases. A meta-analysis was conducted to compare the values of voice acoustic parameters in CI users and nonhearing-impaired controls. The analysis was conducted using the standardized mean difference as the outcome measure. A random-effects model was fitted to the data. Results: A total of 1334 articles were initially evaluated using title and abstract screening. After applying inclusion/exclusion criteria, 20 articles were considered suitable for this review. The age of the cases ranged between 25 to 132 months at examination. The most studied parameters were F0, Jitter, Shimmer and Harmoni Noise Ratio (HNR); other parameters were seldom reported. A total of 11 studies were included in the meta-analysis of F0, with the majority of estimates being positive (75%); the estimated average standardized mean difference based on the random-effects model was 0.3033 (95% CI: 0.0605 to 0.5462; p = 0.0144). For Jitter (0.2229; 95% CI: -0.1862 to 0.7986; p = 0.2229) and shimmer (0.2540; 95% CI: -0.1404 to 0.6485; p = 0.2068) there was a trend toward positive values without reaching statistical significance. Discussion and conclusions: This meta-analysis confirmed that higher F0 values have been observed in the pediatric population of CI users compared to age-matched normal hearing volunteers, whereas the parameters of voice noise were not significantly different between cases and controls. Prosodic aspects of language need further investigations. In longitudinal contexts, prolonged auditory experience with CI has brought voice parameters closer to the norm. Following the available evidence, we stress the utility of inclusion of vocal acoustic analysis in the clinical evaluation and follow-up of CI patients to optimize the rehabilitation process of pediatric patients with hearing loss.摘要： 引言：完整的听觉系统对于嗓音质量与言语韵律的发展及维持至关重要。反之，听力损失会影响言语与嗓音产生相关器官的调节及合理使用。目前已有针对人工耳蜗（Cochlear Implant，CI）使用者的声学嗓音参数评估研究，此前该领域的系统综述作者指出，基础基频（Fundamental Frequency，F0）似乎是评估成人人工耳蜗使用者嗓音变化最可靠的参数。本项系统综述及荟萃分析的主要目的是阐明儿童人工耳蜗使用者的言语嗓音参数与韵律变化特征。 材料与方法：本系统综述的研究方案已注册于国际系统综述前瞻注册数据库（PROSPERO）。我们检索了2005年1月1日至2022年4月1日期间发表于PubMed及Scopus数据库的英文文献。本研究采用荟萃分析比较人工耳蜗使用者与非听力受损对照者的嗓音声学参数值，以标准化均数差作为结局指标，并通过随机效应模型拟合数据。 结果：初始通过标题与摘要筛选共评估1334篇文献，经纳入/排除标准筛选后，最终有20篇文献符合本综述纳入要求。受试对象的检查年龄范围为25至132个月。研究最多的参数为基频（F0）、基频微扰（Jitter）、振幅微扰（Shimmer）及谐噪比（Harmonic-to-Noise Ratio，HNR），其余参数报道较少。针对F0的荟萃分析共纳入11项研究，其中75%的效应量估计值为正值；基于随机效应模型的平均标准化均数差为0.3033（95%置信区间：0.0605~0.5462；P=0.0144）。针对Jitter（标准化均数差为0.2229；95%置信区间：-0.1862~0.7986；P=0.2229）与Shimmer（标准化均数差为0.2540；95%置信区间：-0.1404~0.6485；P=0.2068）的分析结果均呈现正值趋势，但未达到统计学显著性。 讨论与结论：本荟萃分析证实，与年龄匹配的正常听力志愿者相比，儿童人工耳蜗使用者的基频值更高，而嗓音噪声相关参数在两组间无显著差异。言语韵律层面仍需开展进一步研究。在纵向研究设计中，长期佩戴人工耳蜗的听觉体验可使嗓音参数更趋近于正常水平。基于现有研究证据，我们强调将嗓音声学分析纳入儿童听力损失患者的临床评估与随访流程，有助于优化其康复干预效果。